Bartolo Colon scattered seven hits over eight innings for the American League West-leading Oakland Athletics, who stretched their division lead over Texas to 51/2 games with a 1-0 victory over the Rangers and Yu Darvish on Saturday.
The A's won for the seventh time in eight games, and clinched the key division series by beating Texas twice in less than 24 hours.
Colon (16-6) struck out seven and lowered what is already his career-best earned-run average to 2.73. The 40-year-old right-hander became the first to reach 20 victories against Texas, his most victories against any team and the most by any pitcher against Texas.
Darvish (12-9) struck out 10 over seven innings in his fourth 1-0 loss of the season. The right-hander has lost his last four starts, the last two by 1-0 scores, and is winless in his last six.
Even though Darvish struck out the side in the first, Josh Donaldson drew a one-out walk and scored on a two-out double by Brandon Moss into the right field corner. Donaldson was able to get around catcher Geovany Soto when second baseman Ian Kinsler's relay throw was a bit up the line.
Texas has lost all five games on this homestand, and is 2-10 in September.
Darvish had his majors-best 12th game of at least 10 strikeouts this season, and the 20th in 58 career games. He also surpassed 250 strikeouts, becoming only the fourth pitcher to accomplish that within his first two MLB seasons — the others: Tim Lincecum (265 in 2008), Dwight Gooden (276 in 1984, and 268 in 1985) and Herb Score (263 in 1956).
Jon Lester is proving he's Boston's ace again.
Lester pitched eight dominant innings, and the American League East-leading Red Sox dealt the New York Yankees' wild-card hopes another blow with a 5-1 victory.
The 29-year-old left-hander is 6-3 since mid-July with a 2.52 ERA in 12 starts after a rough stretch midway through the season.
"What he's done since the All-Star break has been consistent with how he's started the season," Manager John Farrell said. "A well above-average pitcher, a front-line starter and that's what Jon Lester is."
Lester (14-8) was solid from the start, mixing a sharp cutter with a well-spotted, mid-90s fastball. He gave up one run and three hits, struck out five and walked two for his fourth victory in six starts.
Midway through the season, he was 0-4 in six starts with a 7.20 ERA.
"I knew after what I went through at the middle of the year that it's just a matter of time and things will take care of itself," he said. "I think any time you take someone that's had some success, your confidence is high. When you struggle, that kind of varies from certain starts."
The Red Sox built a 5-1 lead against CC Sabathia (13-13) after five innings. The left-hander gave up five runs and nine hits in six innings.
Joey Votto and Shin-Soo Choo each hit two-run home runs, and the Cincinnati Reds kept pace in the National League Central race with a 7-3 victory over the Milwaukee Brewers.
Homer Bailey (11-10) gave up three runs over seven innings in winning his career-best sixth consecutive decision. Votto drove in three runs.