Jon Lester outdueled Max Scherzer and the Boston Red Sox beat Detroit 2-1 on Tuesday night, ending the Tigers right-hander's chance to become just the second pitcher to open a season with a 20-1 record.
Lester (13-8) lowered his ERA to 1.71 in his past six starts. He allowed one earned run and eight hits with a season-high nine strikeouts and no walks.
Scherzer (19-2), who won his first 13 decisions, lost for the first time since July 13 when the Texas Rangers beat him 7-1.
Roger Clemens is the only pitcher to start off at 20-1 and ended up 20-3 with the New York Yankees in 2001. Rube Marquard was the only other pitcher with a 19-1 record, but lost his next decision in 1912 with the New York Giants.
Boston scored on Will Middlebrooks' two-run single in the fifth after Detroit's Jose Iglesias doubled in a run in the second in the matchup of division leaders.
Koji Uehara pitched the ninth for his 17th save in 20 opportunities and extended his scoreless streak to 25 innings as Boston won for the eighth time in 10 games.
The Tigers lost for the second time in six games despite the return of Miguel Cabrera, who missed three games with abdominal and groin problems. Last year's Triple Crown winner and this year's AL leader in batting average and RBIs went 0 for 4.
Scherzer rebounded from his worst start of the season and allowed two runs and five hits with eight strikeouts and three walks before leaving with runners at first and second and no outs in the eighth.
In his previous outing, he avoided his second loss when Torii Hunter hit a game-ending three-run homer for a 7-6 victory over the Oakland Athletics. Scherzer allowed a season-high six runs in five innings.
On Tuesday, he struck out the side in the first, allowed a single in the second and then pitched two perfect innings.
He started the fifth by striking out Mike Carp before Jonny Gomes singled. Stephen Drew followed with a ground-rule double that went into Boston's bullpen in right-center field on one hop. Middlebrooks then put Boston ahead 2-1 with a single to center.
The Tigers got base runners against Lester in four of the first six innings, but he worked out of three of those jams.
In the second, Omar Infante singled and reached third on a two-out single by Brayan Pena. Iglesias then lined a double to left-center that drove in Infante, but Pena was thrown out easily when he tried to score.
Lester retired the next seven batters, four on strikeouts, before Pena reached first on a fielding error by third baseman Middlebrooks with one out in the fifth. Iglesias struck out before singles by Austin Jackson and Hunter loaded the bases. But Cabrera grounded to shortstop Drew for a force out at second.
Detroit threatened again in the sixth when Prince Fielder singled and took second on a one-out single by Infante. But Lester struck out Matt Tuiasosopo for the third time and retired Pena on a fly out.
NOTES: Boston starters have allowed three runs or fewer in 13 of its past 14 games. ... Detroit's Victor Martinez extended his hitting streak to 10 games with a single in the eighth. ... Red Sox CF Jacoby Ellsbury missed the game with a sore thumb. ... Rick Porcello (11-7) pitches for Detroit against Ryan Dempster (7-9) in the finale of the three-game series on Wednesday night.