Detroit's Justin Verlander notched up his eighth win of the season on Friday, pitching seven solid innings as the Tigers solidified their place at the top of the American League Central with a 7-5 win over the slumping Cleveland Indians.
The Indians (30-30) have lost five on the trot, allowing the Tigers (33-26) to open up a three and a half game lead in the division.
Victor Martinez finished a triple shy of the cycle, hammering an important home run for Detroit against his former team.
National League Central leaders St. Louis strengthened their position with a 9-2 demolition of Cincinnati.
The Cardinals (40-21) were the first in the majors to 40 wins thanks to David Freese, Jon Jay and Pete Kozma, who combined for six hits and seven RBIs to give St. Louis a four game lead over the Reds (36-25) and Pittsburgh Pirates.
Russell Martin scored a run and drove in another as the Pirates produced a major league leading 10th shutout, beating the Chicago Cubs 2-0.
Francisco Liriano pitched seven innings allowing just two hits, striking out eight as the Pirates (36-25) stayed in touch while the Cubs (24-34) sunk deeper in the mire.
It took a Desmond Jennings two-run homer in the bottom of the seventh to interrupt Jason Hammel's shutout bid and help edge the Tampa Bay Rays to a 2-1 win over the Baltimore Orioles.
Tampa Bay (33-27) are fourth in the AL East but still have the Orioles (34-27), New York Yankees (35-26) and Red Sox (37-24) within reach. The Yankees fell 4-1 to Seattle (27-35).
The other AL East team, Toronto (26-34), upset the Texas Rangers (36-24) 6-1, helped by a Melky Cabrera home run, one of three hits to go with his two RBIs.
It allowed the Oakland Athletics (38-25) to steal the AL West lead after their 4-3 win over the Chicago White Sox (25-34).
Nolan Arenado produced a walk-off home run in the bottom of the ninth to help the Colorado Rockies (33-29) to a 10-9 win over San Diego (28-33) in the NL West.
But the Arizona Diamondbacks (35-26) stayed on top with 3-1 win over San Francisco (31-29) while the Los Angeles Dodgers (27-33) beat the high flying Atlanta Braves (37-24) for the second night running with a 2-1 win in 10 innings after Skip Schumaker scored on a wild pitch.