Stephen Strasburg's return for the Washington Nationals from the disabled list went smoothly but he was unable to prevent the Cleveland Indians recording a 2-0 victory on Sunday.
Strasburg, who had not pitched since May 31 due to a strained muscle in his back, appeared in solid form as he allowed just one run over five innings.
Cleveland starter Corey Kluber outdid him though as he pitched eight scoreless innings and struck out eight batters.
Carlos Santana had an RBI single against Strasburg in the fourth inning and Jason Kipnis added a sacrifice-fly in the eighth to produce Cleveland's runs in a game where they only got four hits.
In Baltimore, Chris Davis blasted his Major League-leading 23rd home run of the season to help the Orioles to a 6-3 win over the Boston Red Sox.
Davis, who is also second in the American League in batting average (.335) and RBIs (60) added an RBI double as Baltimore grabbed a 5-0 lead and ended Boston starter Jon Lester's game after five innings.
Nick Markakis had four hits and Manny Machado extended his hitting streak to 14 games for the Orioles.
Baltimore (40-30) inched closer to first-place Boston (42-29), who now hold a 1-1/2 games divisional lead.
In Los Angeles, the New York Yankees squandered most of their 6-0 lead in the final inning, before Mariano Rivera struck out Albert Pujols with the bases loaded to end the game and record a 6-5 victory over the Angels.
CC Sabathia worked eight scoreless innings but was charged with two runs in the ninth and then replaced before reliever David Robertson was charged with allowing two runs, and Rivera one before he completed his 24th save of the season.