After several weeks of inconsistency, Lester has been in top form in his last two starts, and he turned in his third quality start in four outings on Saturday.
"It's always gratifying to see the fruits of your labor, for lack of a better term," Lester said. "It's been a grinding season. I said back a month or so again, 'I'm not giving up. I'll keep working hard and things will turn.' The past handful of starts, I feel like they have."
The left-hander improved to 7-10 while lowering his ERA to 5.03.
Offensively, Lester and the Red Sox got an early boost from Adrian Gonzalez, who belted an opposite-field two-run homer with two outs in the first inning.
Pedro Ciriaco continued to be an absolute nemesis to the Yankees, going 4-for-4. The shortstop raised his average to .343 on the season and is hitting .517 (15-for-29) against New York with nine runs, three doubles and seven RBIs.
"A bunt for a base hit, a hit-and-run double; a stolen base; a curvebvall to right field; a base hit to center field on a fastball -- that's a good day," said Red Sox manager Bobby Valentine. "That doesn't surprise me. It amazes me that he is who he is with that kind of talent and hasn't been utilized before."
There was also some strong teamwork from the bullpen. Andrew Bailey, who has finally joined the Sox-Yankees rivalry the last two days, struck out Derek Jeter to open the eighth. And after Bailey gave up a single to Nick Swisher, lefty Craig Breslow came on and, with one pitch, induced a 3-6-3 double play.
Alfredo Aceves worked around one hit in the ninth and posted his 25th save.
It makes you wonder how different the Red Sox's record -- 59-62 -- could have been if they combined all facets of the game as well as in this one.
"We still have it," said Valentine. "We've had it. We've got it. We just haven't used it as often and saved it up."
With 41 games left, Valentine's team has left itself no choice but to play lights-out baseball the rest of the way in order to make something of this season. With the AL Wild Card-leading Orioles and Tigers squaring off on Saturday, the Red Sox were guaranteed to be 6 1/2 games back of a Wild Card berth at the end of the night.
Can the Sox do the opposite of what they did last year, when they had a nine-game lead in September and didn't make the postseason?
"Regardless of what happened last year, any time you're in position where you're down but we're not necessarily out, you've got to keep grinding away, showing up every day and playing hard," said Lester. "I don't think this team has ever been criticized for its lack of effort. Everybody shows up and plays hard every day."
After allowing the first two batters to reach in the first inning, Lester escaped. He had a shutout going through 3 2/3 innings, but Curtis Granderson ended that by smashing a homer over the wall in center, slicing Boston's lead to 2-1.
Ciriaco, who seems to contribute every time he starts, ignited a fifth-inning rally with a one-out single to right and finished with four hits. Four of Ciriaco's six career games of three hits or more have come against the Yankees.
"I enjoy every time I'm in the lineup, and it doesn't matter what team," said Ciriaco. "But when we play against the Yankees, it's like [the playoffs]."
Nick Punto followed by hammering an RBI double into the corner in right. Punto advanced to third when right fielder Andruw Jones had a hard time coming up with the ball, taking an error. Jacoby Ellsbury and Carl Crawford couldn't get Punto home, so Lester clung to a 3-1 lead.
There was an insurance run in the ninth. Scott Podsednik led off with a double and Ciriaco -- who else? -- ripped a double to left. Podsednik scored on a wild pitch.
For all the storylines that developed during the day, the most important one was Lester.
"When you look up at the numbers and you see it, you kind of step back," Swisher said. "You know that's not the type of pitcher that he is. Tonight, you got the best Jon Lester that we've seen in a while."