Bjorn Borg won his second consecutive Wimbledon singles title today after Jimmy Connors nearly achieved one of the most dramatic final-set comebacks in the 100-year history of the tournament.

Connors battled back to 4-4 from 0-4 and two break points him for 0-5 in a thrilling fifth set, then lost his serve as Borg dramatically seized the last eight points and the match, 3-6, 6-2, 6-1, 5-7, 6-4.

At the end of the 3-hour 14 minute, clash of wills between the two best players in the world, a fitting climax to Wimbledon's centemary celebration, the usually stolid Borg raised his arms over his head, arched his back and gave an ecstatic look toward the clear blue heavens.

As the crowd of more than 14,000 sum-splashed spectators who packed the center court of the All England Lawn Tennis and Croquet Club thundered applause. Borg turned to the competitor's guest box where his fiancee, Mariana Simionescu, and his coach, Lennart Bergelin, were seated. The 21-year-old Borg put his hands over his icy, close-set eyes as if he couldn't believe he had won.

Later, having removed the headband that holds his tangled blond locks in place. Borg accepted the gold championship cup from the Duke of Kent and held it aloft with one hand.

"I thin I'm even a little happier this year than last because I played Jimmy, in the final and I wanted to beat him very badly." Borg said afterward. "He's been beating me a lot of times before, and I lost to him in Forest Hills, in a very close final. I think this is for sure my happiest win."

Borg, just 26 days past his 21st birthday, now has won two Wimbledons, two French Opens, three U.S. pro titles, one Italian and one WCT championship, a more spectcaular array of major titles than any other player his age in the same's history.

The only other man to win two Wimbledon titles at such a tender age was Wilfred Baddeley. He was the youngest men's champion of all time (19 years, 5 months, 23 days) in 1891 and repeated in 1892.

When Borg hammered the seventh of his eventual eight aces to hold his served at love for 4-0, everybody, even Connors, thought the match was over.

If looked as if it might end with a 6-0 set as Connors, struggling as he had for long stretches in the second and third sets, neted a forehand coming in to give Borg a second break point after one deuce

But Connors finally held serve for 1-4 after three deuces, and then summoned his last big effort.

He started his sixth-game with a running forehand down-the-line passing shot. It was a fighting stroke that seemed to signal sa resurgence in his legs and his gleaming steel racket.

SUddnely for the next three games he was the Connors who was here in 1974, jerking Borg around the court with flat, hard strokes to the corners, lunging for acrobatic volley, uncoiling into ground-strokes, volley, overheads with a grunting ferocity no other player can initiate.

He shoved Borg to 0-40 and, after the Swede had saved two break points with a netted return and an ace that kicked chalk on the sideline, broke with a flying, backhand cross-court volley.

Connors held his own serve from 0-30 and slapped his thing, exhorting himself, as he prepared to receive serve in what suddenly appeared as the most important game of the match.

Connors made a good return and cracked another running forehad down-the-line winner off Borg's backhand first volley. Borg's hit a forehand wide: 0.30

Borg made a forehand volley on the sideline off a floating return, but Connors hit a forehand return that crawled over the net for a winner 0.40

Connors lobbed wide, but on the second break point he whacked a hard forehand approach shot cross-court and barreled he behind it. Borg went down the line with a backhand and Connors lunged and made a backhand cross-court volley. Borg off like the wind ran it down and smacked a screaming forehand down the line, but Connors anticipated and intercepted it with a forehand volley winner into the open court, it was 414.

Connors was hyped up now, bouncing like a prize tighter who can't wait to get out of his corner after a late flurry in the previous round. He sensed the kill. Borg, understandably dejected, looked weary. He bent over and his breath came in deep gasps.

On the first point of the ninth game. Connors devoured a high backhand volley. But then he double faulted, and the energy seemed to drain from him.

Borg made a forehand stop-volley off a hard forehand right at him for 15.30. Connors sailed a backhand way over the baseline for 15-40 and stomped on the grass in a fit of frustration. He hit another backhand just long, off a rally, and his expression was that of a miserable man who had accomplished something - and then thrown it all away.

Borg. up 5-4, served a strong game to hold at love. On the final, winning point, Connors hit a half volley that floated deep but sat up in the grass. [TEXT ILLEGIBLE] for bowling a 4-2 lead and broke at love in the 12th game. He hit a winning lob on the baseline for the set after two winners and a Borg double fault had put him in the hole.

But Connors played two awful winners on his serve and was broken twice to go 0.4 down in the fifth. "I think if I had started out a little lighter and won the first game it might have been different," he said.

It almost was different anyway.

He throught the tournament. I played my best tennis when I was down - 2.5 in the fourth set to Marty Riessen, won it 8.6; down two sets to one to Stan Smith. I won it in five," said Connors, who was runner-up for the second time, earning $13,000 compared to borg's $25,800.

"I should go out and play my best tennis when I'm ahead. Then there's be no stopping me, right?" CAPTION: Picture 1, Bjorn Borg appears overcome with joy winning his second successive Wimbledon men's single championship. UPI; Picture 2, Bjorn Borg smacks a backhand en route to his victory in the men's singles [WORD ILLEGIBLE] UPI; Picture 3, Connors, making a running forehand return.