Adam Wainwright joined the 20 win club Monday night at Wrigley Field. (photo/MLB)

Adam Wainwright joined the 20 win club Monday night at Wrigley Field. (photo/MLB)

Adam Wainwright hit the 20-win mark for the second time in his career, joining L.A.’s Clayton Kershaw as the only pitchers in the majors with 20 this season, as the Cardinals moved a step closer toward their second straight division title with an 8-0 win over the Chicago Cubs.

Pittsburgh won, so the Cardinals magic number to clinch the Central is four.  The Pirates magic number is two from clinching a playoff berth.

Wainwright went seven innings and allowed just three hits and a walk.  He gave up a double to Anthony Rizzo with two out in the first and did not allow anything else until back-to-back singles with two out in the seventh.  By then, the game was well in hand.

The Cardinals pounded Travis Wood for seven runs and eight hits over five innings, adding four in the fourth and three in the fifth on the way to their eighth win in 10 games.