Stephen Strasburg met every reasonable expectation, and exceeded several ridiculous ones, in his nearly flawless return to the major leagues Tuesday night at Nationals Park.

Where’s the rust or the lost command? Who returns to the big leagues after 382 days away for elbow surgery with more precision and better efficiency than when he left? Who fans one Dodger on a 99 mph fastball, barely allows an audibly struck ball in five innings, but has the touch and finesse to fan both Matt Kemp and Andre Eithier on 90 mph change-ups?

Now that the Lexington Legends and the Hickory Crawdads are behind him, Strasburg apparently knows exactly what to do with lesser rivals like Los Angeles. The Dodgers managed to hit only one ball loudly — a line-drive out directly to the rightfielder — as Strasburg left with a 3-0 lead after five innings. His maximum was supposed to be four innings, but he made the Bums look so bad he earned a fifth frame and still needed only 56 pitches.

Too bad for the Nats, he had to leave. They stunk subsequently and lost, 7-3.

“Totally relaxed, totally in control, strong at the end, he was special,” said Manager Davey Johnson after Strasburg’s first pitch was 96 mph, his last 97. “Shoot, he just made it look easy . . . Fun watching, like he hadn’t been out. A couple of times, he let it loose on strikeouts, but it was just 96 on the knees and corners all night and that change-up is almost unhittable.”

Strasburg faced 17 Dodgers, retired 15, struck out four (all swinging) and permitted only two hits, one of them a grounder to shortstop than should have been fielded. This wasn’t June 8, 2010 for theatrics, not by many miles, not with a small crowd; perhaps 10,000 of the 29,092 who bought tickets stayed home after an all-day rain, lending a small-buzz atmosphere to a night of big importance to the Nationals’ future.

But for efficiency and progress as a polished pitcher, evidence dripped from every aspect of this performance that Strasburg, the perfectionist, has used his year in rehab exile to fine-tune flaws perhaps only visible to him.

“Seize the day,” said Strasburg, summarizing his approach to “every day” of the last year. “The last year, I didn’t waste a minute waiting for this game. I was always working on something . . . I’m really trying to be a pitcher out there, not just light up the radar gun every time.”

Effortless, precise, in command of his fastball and changeup, though not yet his curve consistently, Strasburg produced only the second scoreless start of his career; his average of 11.2 pitches an inning was his best ever.

“Guys don’t want to get to two strikes against me, so if you make quality pitches early in the count, you can get quick outs,” said Strasburg, who introduced himself to 82 percent of Dodger hitters with a strike. “I think my command of my fastball is better than it was before,” he said, “because I don’t try to dial it up every time.”

If all this sounds familiar, it should. It’s the same theory of better efficiency that made Jordan Zimmermann so much better this season.

“Stephen’s growing up mentally as a pitcher, just the way Zim has learned to get outs with two-seam [sinkers] early in the count,” said GM Mike Rizzo. “You’re seeing little touches. He never threw change-ups to right-handed hitters before. Tonight he struck out [MVP favorite] Matt Kemp on one.”

As for his much-monitored fastball, which averaged 97.3 mph in ’10, his 41 heaters on a 61-degree night averaged 96.3. If Strasburg regains speed at the same pace as Zimmermann did this year, he’ll be right back at his old level, if not a tad higher, by next season.

Strasburg, however, is always an I’ll-believe-it-when-I-see-it sort. He still thinks his command “comes and goes.” He found his curveball release point in mid-game, but not early. As for his overall stuff, with six swings and misses on 56 pitches, Strasburg said, “It’s not where it was [in ’10] yet, but that’s to be expected . . . This is probably as close as it’s going to get this year. Get stronger. Stay healthy. Then come back better than ever in ’12.”

For one night, almost everything Strasburg set as goals for himself for the past year — better efficiency and lots of soft contact rather than long-at-bat strikeouts — was on display instantly. It’s not that easy. But, in his first time back in Nats Park, Strasburg showed how he’s used the last year as a baseball graduate school to condition his body and refine his mound tactics.

As for composure on stages where others tense up, that’s not him. “No butterflies. It seemed like slow motion out there,” he said. Of course, pitching coach Steve McCatty “was a nervous wreck,” Johnson said.

If the history of many pitchers who recover from Tommy John surgery, like Zimmermann, holds true for Strasburg, then he will have erratic games when his “new elbow” doesn’t feel quite right and either his stuff or his control isn’t crisp. But are we entirely sure Strasburg is like other pitchers?

In his past three outings, at Class AAA, then Class AA and now against the Dodgers, he’s pitched 16 innings and allowed only one run on five hits while fanning 15 and walking none. That’s the most effective three-game span, regardless of level, since he turned pro.

Last year, Strasburg had few flaws. But his dominance and aura seemed to imply an ERA better than the 2.91 mark he produced. In every game, he allowed several hard-hit balls. Tuesday, Strasburg seemed intent on literally silencing the Dodgers’ bats. A soft leadoff liner over shortstop in the first inning by Dee Gordon for a speedster’s double and a grounder under Ian Desmond’s leisurely glove for a single were the only blemishes.

To sane followers of baseball, Strasburg is probably still at least six months from the arm strength he’ll eventually have; and it may be next summer, as it was with Zimmermann, before we see the real Strasburg 2.0.

If Strasburg gets much better than he was in this debut-with-a-new-elbow, baseball may see a marriage of talent and polish, continuing education and relentless efficiency that’s almost unique in one so young.

That’s far from a certainty. But the promise of such a thing, of a Strasburg who’s been given a fresh elbow, plus a year to work on everything about his perfectionist self that he didn’t like, has now become a distinct and slightly dizzying possibility.