NEW YORK — This wasn’t just what the Red Sox needed. Jon Lester’s start was exactly what the Red Sox desperately needed.

Nine innings pitched. No runs allowed. One losing streak snapped.

And did we mention the nine innings pitched?

The Red Sox’ pitching staff was depleted, with every member of the bullpen except closer Jonathan Papelbon having pitched in Wednesday’s debacle at Tropicana Field.

But Lester gave them more than innings; he gave them good, strong, and mostly quick innings.

If this wasn’t the biggest win of the season to date for the Sox, it made its way onto a short list. And the Sox mostly have Lester to thank.

“He pitched really, really well,” concluded manager Terry Francona. “You show up to win. He did that, and on top of that, he stays out there the whole time.”

Lester gave the Sox nine innings, but for a time, it looked like he might not survive the first. Lester issued walks to Johnny Damon and Derek Jeter, the first two hitters he faced, and it was evident that he was less than pleased with home-plate umpire Wally Bell’s strike zone.

After the walk to Jeter, Lester stared down Bell from the mound, prompting a visit from catcher Jason Varitek. On the telecast, Varitek could be seen making an emphatic point to the young starter.

And what was Varitek’s message?

“We always tend to keep those things private,” said Varitek, a smile creasing his face.

Said Lester, “There are times when you need to get your butt kicked because you’re pouting about some calls you didn’t get. And there are times when he’s telling you, ‘You’re right there,’ and reinforcing things for you.”

Lester was asked which best described what Varitek did last night in the fateful first.

“A little bit of both,” Lester said.

Whatever Varitek said, whatever his message — a pat on the back, or a kick to the backside, it worked. Lester got Bobby Abreu to roll over into a force-out, then fanned Alex Rodriguez and Jason Giambi each, needing only seven pitches combined.

“A game can change so much early on one pitch or one at-bat,” Francona said. “If he makes a mistake to either one of those guys, it’s 3-0.”

Instead, the first inning was over, and really, so were the Yankees. Expertly mixing his cutter, his sinker, his changeup and a four-seamer, Lester retired 19 of the next 21 hitters he faced.

He regained his focus and his composure and went back to attacking the Yankee hitters. Tellingly, he didn’t walk another batter after the first two, evidence of how well he — with Varitek’s help — adjusted.

Synching up with Bell’s strike zone wasn’t easy “especially in the first inning, because you’re trying to get into a rhythm,” Lester said.

Last year, or the year before, Lester might not have righted himself so expertly.

“I think he’s more capable as a pitcher. … He has fewer limits,” Varitek said.

What Varitek might have added was that Lester has matured on the mound.

“He’s growing up right in front of us,” Francona said. “He didn’t let it affect him. He handled it like a major-league pitcher.”

Thanks to three double plays, after the first inning, Lester faced just two batters over the minimum. That he threw 26 fewer pitches than in his no-hitter against Kansas City, on May 19, speaks to his efficiency.

While he cruised, the Sox offense stirred against Andy Pettitte. It was 4-0 after two, 5-0 after four, and 6-0 after five, by which time Pettitte was gone from the game.

In pitching the first complete-game shutout for a Red Sox lefty in Yankee Stadium since Roger Moret, almost 35 years ago to the day, there was some irony that Lester far outpitched Pettitte, the pitcher to whom he’s been frequently compared.

Both are big, strong lefties who rely on a cut fastball, and scouts have often said that Lester might eventually develop into a pitcher of Pettitte’s caliber.

“I can see why people say that,” said Francona, nodding in agreement and ticking off some of the many similarities.

“I definitely have watched him,” said Lester, “and tried to mold myself after him. We have some of the same stuff — a (sinking) fastball, a cutter, a curve and change — and he’s had a lot of success in his career.”

But while Pettitte, at 36, has seen his better days, Lester is progressing all the time. Given the circumstances last night, however, he could hardly have been better.

smcadam@projo.com