Lester pitched a three-hitter for his fourth career shutout, and the A's beat the Minnesota Twins 3-0 on Thursday night.
The All-Star left-hander struck out eight, walked two and only allowed two runners past first base in the 11th complete game of his career. He pitched out of a two-out, bases-loaded jam in the sixth but was otherwise stellar.
Lester (12-7) was making second start since being acquired at the trade deadline as part of the blockbuster deal that sent Cuban slugger Yoenis Cespedes to Boston.
The deal rankled many Oakland fans. Others welcomed the trade and showed their approval with chants of "Lester! Lester!" when the veteran pitcher came out to pitch the ninth inning.
"We all know what Cespedes did for this organization and how well he's liked," Lester said. "Just coming over here, you don't want to (mess) that up. You want to make the trade look like it had a purpose and it was good."
Lester retired the first 15 batters while allowing only three balls out of the infield. Former A's catcher Kurt Suzuki ended the bid for perfection with a leadoff single in the sixth.
The former Boston ace improved to 6-0 with 1.21 ERA over his last 10 starts.
"You could see from the onset that he was going to be tough to score on," Oakland manager Bob Melvin said. "Not only is he able to pitch that type of game but he's also a guy that gives the bullpen a rest. That's exactly what he did tonight."
Stephen Vogt homered and Derek Norris hit an RBI double to help Oakland become the first team in the majors to reach 70 wins.
Melvin became the eighth active manager in the majors and 76th overall to reach 800 career victories. Two of them have come with Lester on the mound, showing why general manager Billy Beane made the deal with the Red Sox.
Chris Colabello and Oswaldo Arcia had the other hits for Minnesota, which has lost 10 straight to Oakland.
"Lester was the story of the night," Twins manager Ron Gardenhire said. "He has all the pitches. He can do all those things."
Vogt snapped an 0-for-23 skid with his sixth home run of the season, a two-run shot off Yohan Pino (1-4) in the third.
Back-to-back doubles by Brandon Moss and Derek Norris in the fourth made it 3-0.
EAGER FULD JUMPS THE GUN
Melvin wanted Jonny Gomes to pinch-hit in the eighth inning and had Sam Fuld ready to run if Gomes got on base. But Fuld got overanxious and ran out to first base to run for Alberto Callaspo before being called back to the dugout.
"He was just a tad eager," Melvin said. "He probably has a games (played) clause in his contract."
Twins second baseman Brian Dozier just missed hitting a tying three-run home run in the sixth inning when his ball curved just wide of the left-field foul pole.
"Even when it landed I still thought it was fair," Dozier said. "You go from a very high to a very low in a short time."
Twins: First baseman Joe Mauer (strained right oblique) was given the day off after going 1-for-6 in his first two rehab starts with Single-A Cedar Rapids. There still is no timetable for Mauer's return to the big league club.
Athletics: Shortstop Jed Lowrie was held out of the starting lineup with a bruised right index finger. He pinch hit with two on in the sixth and flew out to right. Melvin indicated Lowrie would most likely start Friday. ... First baseman Kyle Blanks (calf) ran the bases for the second time and could begin a rehab assignment this weekend.
Twins: Right-hander Kyle Gibson (10-8) has pitched extremely well against the AL West, winning four of six starts this season while crafting a 2.50 ERA. He gets the ball Friday night against the A's.
Athletics: Left-hander Scott Kazmir (12-4) has a 1.92 ERA in 10 starts at the Coliseum this season. He beat the Twins in Minnesota on April 7 when he allowed three runs over six innings.
Lester, A's Shut Out Twins
Jon Lester picked up his 12th victory of the season in the A's 3-0 win over the Twins.