Stipe Miocic tags Francis Ngannou with a right hand in their heavyweight championship fight Saturday night at UFC 220 in Boston. (Mike Lawrie/Getty Images)

BOSTON — The last four times UFC heavyweight champion Stipe Miocic stepped into the octagon, he laid waste to his opponent via knockout within the first round. That’s the kind of track record that will earn a 6-foot-4, 246-pound fighter the fearsome designation of “Baddest Man on the Planet.”

Of course, the planet covers a whole lot of ground beyond Miocic’s native Cleveland, and from halfway around the globe in the Central African nation of Cameroon hails a man who some were saying was even badder. Francis Ngannou is 6-5, 263 pounds, all of it sculpted from granite. He, too, had devoured his four most recent foes in less than a round. When this fighter connects just right, an eerie “oooooh” emanates from astonished onlookers.

On Saturday night, when Miocic and Ngannou collided in the main event of UFC 220, no one at TD Garden was expecting to see a second round. But they did. They saw a third, a fourth and a fifth, too. They did not experience a Ngannou-induced “oooooh” exclamation.

Miocic fought a well-rounded fight, winning the striking battle and dominating the wrestling on the way to retaining his belt with a unanimous decision. It was the 35-year-old’s third successful title defense, which is more than any previous UFC heavyweight champ can boast. Thus he can lay claim to the honor of being the “Baddest Man Ever.”

Miocic (18-2) avoided the challenger’s wild offense early, then took him to the canvas to sap his strength. Ngannou (11-2) was simply incapable of keeping the fight where he needed it to be in order to be successful. It was a masterful performance by the champ, who now must be considered one of the greatest — and arguably the greatest – heavyweights in UFC history.

The battle of big boys was one of two championship fights on the 11-bout card, the other being Daniel Cormier’s successful — and redemptive — defense of the light heavyweight belt with a dominant second-round TKO of Volkan Oezdemir.

Here is a round-by-round recap:

Heavyweight championship: Stipe Miocic beats Francis Ngannou (Unanimous decision – 50-44 on all cards)

Round 1: There was a buzz in the building as perhaps the most highly anticipated heavyweight title fight in UFC history got underway. When they touched gloves after the referee’s instructions, it was the most cordial they would be for five minutes. Miocic started with distance-keeping kicks, but Ngannou came right after him with wild punches. Miocic’s movement kept nearly all of these from landing, but the champ did have a bruise under his right eye. Miocic connected with a hard right, and the crowd roared … but Ngannou wouldn’t move. But with just under two minutes left, Miocic got his opponent down and started throwing elbows. When Ngannou finally worked his way back to his feet, he had less offense and Miocic was nailing him with punches.

Round 2: The challenger was visibly worn out. His mouth was open, and his energy was low. Still, he would flail a wild right hand that would make excite the crowd with its possibilities. Miocic was having none of it. He went for the takedown and got it, and wore down Ngannou on the canvas. He didn’t inflict much damage, but there was nothing coming his way as long as he was on top of the big challenger. The champ was having his way.

Round 3: More of the same. Ngannou’s offense consisted of nothing but the occasional flailing overhand right, and Miocic remained out of range until it was time to get the takedown and sap even more energy out of his challenger. The champ was inflicting some damage from top control, though not enough to end the fight. But Ngannou was looking nothing like the fearsome hulk he’d been in recent fights. When the round ended, the challenger moved slowly to his corner, where his cornermen began admonishing him to show some life.

Round 4: Miocic wasted no time. As soon as Ngannou moved forward to strike, the champ grabbed a leg and took the fight back to the canvas. He had the challenger on his knees, seemingly unable to get back up. Miocic connected with an unending assortment of short punches, lefts and rights that snapped back the head of his fatigued opponent. He added knees to the sagging midsection, then elbows to the head, then hard right hands to the body. This was turning into a relentless beatdown. Ngannou seemed undestructible, yet he appeared to have nothing left with which to threaten the champ.

Round 5: Ngannou staggered out of his corner, his chest heaving, his mouth open, his eyes glassy. Miocic appeared fatigued, too, but from the volume of punches he had thrown. The champ quickly got the fight into a clinch against the cage, but he couldn’t get the takedown. After the two were separated, Miocic maintained distance and Ngannou stumbled forward trying to muster … something. But he had nothing. The fight ended in a clinch against the cage. And at the horn the champ walked away with his arms raised. It was not the finish anyone in the building expected, no there were no boos, just many cheers for the man who now is the longest-reigning heavyweight champ in UFC history.

Here are the rest of Saturday night’s results:

Light heavyweight championship: Daniel Cormier def. Volkan Oezdemir via TKO (Round 2, 2:00)

Champions don’t often need to find redemption in their fights, but that was the circumstance facing Cormier. He was last seen being brutalized by Jon Jones in July. Though Jones failing a drug test changed that KO to a no contest in the record book, with Cormier given back the belt he’d relinquished, images of a beatdown don’t automatically disappear. You have to face them and extinguish them.

Cormier (20-1, 1 NC) erased every bad memory.

Facing a man who had earned his title shot by shockingly laying waste to a pair of 205-contenders — each within a minute — the champ proved what he had been saying throughout the pre-fight buildup: Oezdemir (15-2) was not on his level. The 38-year-old Cormier out-struck the striker in the opening round, then took him to the mat later in the round and almost got the finish in the closing seconds before the horn.

He then opened the second looking supremely confident, and Oezdemir — who less than a year ago was making his UFC debut in a split-decision win over a mid-level contender — appeared in over his head. Cormier did not fear the man’s power, so the onetime Olympic wrestler committed fully to a takedown and quickly moved to a crucifix position that rendered the challenger’s arms unable to defend. From there Cormier rained down punches until referee Kevin McDonald had seen enough and pulled the champ away.

The crowd roared mightily, and that had to lift Cormier, who’d inexplicably spent much of his career as an unpopular fighter. Apparently that’s all over — as is the Jon Jones hangover.

Featherweight: Calvin Kattar def. Shane Burgos via TKO (Round 2, 0:32)

Burgos came into the fight undefeated and exited it having shown that he can take a punch. A lot of them. From all angles.

Kattar led the dance from start to finish, spending the first round peppering his opponent with a heaping helping of crisp jabs supplemented by head-snapping right crosses. In posting his 10th straight victory, he lived up to his nickname of “The Boston Finisher.”

Boston vs. New York battles in any sport are fire, and this one had the crowd roaring with every connection by Kattar (18-2) and chanting his name. Burgos (10-1) came with some fight in him, too. He did have a brief spell in the middle of Round 1 when he got the better of a couple of exchanges. But his night ended suddenly in the opening moments of Round 2 when Kattar staggered him with a hard right hand and pounced without pause.

Bantamweight: Gian Villante def. Francimar Barrosso via split decision (30-27, 30-27, 28-29)

For three rounds, Villante stalked and fired away but missed more than he landed, because Barrosso retreated more than he engaged. For much of those 15 minutes, the fans sat on their hands when they weren’t booing.

Still, it was a much-needed win for the 32-year-old New Yorker (16-9), who came in having lost two straight fights and three out of four.

The slow-motion dance unfolded with Villante plodding around the cage and Barroso (19-7, 1 NC) mostly moving backward. (“Moving” might be an exaggeration.) The Brazilian did attack with the occasional kick to Villante’s legs, which were firmly planted at all times. But Barrosso couldn’t do anything to halt Villante’s glacial attack, other than stay out of range of the heaviest punches aimed his way. That was not enough.

Bantamweight: Rob Font def. Thomas Almeida via TKO (Round 2, 2:24)

Font, one of several Boston-bred fighters on the card, gave the home crowd a thrilling finish of a Brazilian who not long ago was one of the most promising contenders in the 135-pound division.

After a back-and-forth first round in which each man got in his licks, Font (15-3) hurt Almeida with a right cross early in the second and took him to the canvas, a finish seemingly close. But Almeida (21-3), who had won his first 20 pro fights before dropping a couple over the last year and a half, survived and fought on, bloodied and bleary-eyed.

Font patiently stalked him and eventually staggered Almeida with a head kick, then followed with a series of right hands that finished the job. For Font, a 30-year-old who went piled up an 11-fight win streak before splitting his last four, this was the biggest win of his career.

PRELIMS RESULTS

Featherweight: Kyle Bochniak def. Brandon Davis via unanimous decision (30-27, 29-28, 29-28)

Welterweight: Abdul Razak Alhassan def. Sabah Homasi via KO (Round 1, 3:47, punch)

Flyweight: Dustin Ortiz def. Alexandre Pantoja via unanimous decision (29-28, 29-28, 29-28)

Featherweight: Julio Arce def. Dan Ige via unanimous decision (30-27, 30-27, 29-28)

Featherweight: Enrique Barzola def. Matt Bessette via unanimous decision (30-27, 29-28, 29-28)

Lightweight: Islam Makhachev def. Gleison Tibau via KO (Round 1, 0:57, punch)