Lester stars in Red Sox win
Boston Red Sox lowered their magic number to six and dealt another blow to the New York Yankees' wild-card hopes with a 5-1 win at Fenway Park.
Jon Lester limited the Yankees to one run on three hits over eight innings, striking out five, while Mike Napoli, Jonny Gomes and Shane Victorino had two hits apiece for the Red Sox.
Oakland were 1-0 winners against Texas, Bartolo Colon striking out seven over eight innings of scoreless ball as the Athletics stretched their lead atop the AL West to 5 1/2 games over the Rangers.
The Baltimore Orioles failed to gain ground in the wild-card race as they went down 4-3 in Toronto, Colby Rasmus connecting for the second straight game and Esmil Rogers pitching six solid innings for the Blue Jays.
Asdrubal Cabrera and Lonnie Chisenhall went deep during a five-run fourth frame as the Cleveland remained in wild-card contention with an 8-1 win against the Chicago White Sox.
Also in AL action, 6 2/3 shutout frames from Doug Fister helped the Kansas City Royals edge the Detroit Tigers 1-0 to stay in the hunt for the second AL wild-card berth, the Tampa Bay Rays won 7-0 against the Minnesota Twins and the Los Angeles Angels overcame the Houston Astros 6-2.
The Pittsburgh Pirates moved into a tie for first in the National League Central thanks to a 2-1 victory over the Chicago Cubs, Marlon Byrd's tie-breaking solo shot in the bottom of the seventh inning proving decisive.
The result got the Pirates level with the St Louis Cardinals, who went down 4-1 against Seattle in interleague play. James Paxton tossed six scoreless innings for the Mariners.
Atlanta trimmed their magic number to four with a 2-1 win against the San Diego Padres, 7 1/3 scoreless innings from Kris Medlen spurring the NL East-leading Braves, while Joey Votto and Shin-Soo Choo each hit two-run homers as the Cincinnati Reds continued their play-off push with a 7-3 triumph over the Milwaukee Brewers.
Henderson Alvarez's seven scoreless frames propelled the Miami Marlins to a 3-0 win against the New York Mets in game one before back-to-back homers from Daniel Murphy and Lucas Duda secured the Mets a double-header split with a 3-1 success in game two.
Elsewhere in NL action, Hunter Pence had seven RBI as the San Francisco Giants thrashed the NL West-leading Los Angeles Dodgers 19-3 at Dodger Stadium to keep the home team's magic number at four, the Washington Nationals' seven-game winning run ended in a 5-4 loss to the Philadelphia Phillies and the Arizona Diamondbacks toppled the Colorado Rockies 9-2.