Tampa Bay and Texas started play one-half game ahead of Cleveland, which was at Kansas City, in race for the two wild-card spots.
Myers had a second-inning solo shot and hit a two-run double during a four-run fifth. Cobb (9-3) allowed two runs, six hits, one walk and had 10 strikeouts.
PADRES 2, PIRATES 0
In Pittsburgh, Andrew Cashner carried a perfect game into the seventh inning and faced the minimum 27 batters in a one-hitter that sent San Diego past Pittsburgh.
Cashner (10-8) retired his first 18 batters before Jose Tabata grounded a clean single into right field leading off the seventh. Tabata was erased when Andrew McCutchen grounded into an inning-ending double play, and the right-hander cruised the rest of the way for his first complete game in 31 career starts.
TIGERS 4, MARINERS 2
In Detroit, Rick Porcello struck out 10 in six innings and Detroit beat Seattle to move a step closer to their third consecutive AL Central title.
Victor Martinez broke a 1-all tie in the sixth with a run-scoring single, and Omar Infante followed with his own RBI single.
Porcello (13-8) allowed a run and five hits with two walks, falling one strikeout short of his career high.
The Tigers entered with a five-game division lead over Cleveland.
REDS 6, ASTROS 1
In Houston, Johnny Cueto threw five scoreless innings in his return from the disabled list and Zack Cozart homered and drove in four runs to help Cincinnati to a win over Houston.
Pitching for the first time since straining the muscle below his right shoulder June 28, Cueto (5-2) allowed five hits and struck out five with one walk for the
Cincinnati moved five games ahead of Washington for second NL wild card.
ROYALS 7, INDIANS 1
In Kansas City, James Shields kept Cleveland off balance for six solid innings, Salvador Perez led a scrappy Kansas City offense and the Royals pounded Cleveland to open a series with playoff implications.
Shields struck out a season-high 10 for the Royals (79-71), who moved within 2 1/2 games of the AL’s second wild-card berth.