In St. Louis, John Tudor pitched a one-hitter and Andy Van Slyke and Terry Pendleton hit consecutive home runs in a five-run first inning to lead the Cardinals over Chicago.
An turnout of 39,203 at Busch Stadium watched St. Louis make the most of eight hits in four-plus innings against Cubs starter Scott Sanderson (5-5). Tudor (14-8) won for the 13th time in his last 14 starts with a six-strikeout, one-walk performance.
Vince Coleman, Willie McGee and Tommy Herr had two hits each for St. Louis, with Coleman and McGee scoring two runs apiece and major league leader Coleman stealing his 75th base.
Leon Durham's ground single just beyond the reach of Cardinals first baseman Jack Clark's reach in the sixth inning was the Cubs' only hit off Tudor, who faced only 29 batters.
The Cubs pulled off an unusual triple play, the first in the NL this season and first against St. Louis in nearly five years.
With Clark and Van Slyke on base in the eighth inning, Pendleton lined to first baseman Durham, who, in attempting to force Clark off second base, was late with his throw to shortstop Chris Speier.
As Van Slyke retreated to first, Speier's throw to Durham hit the Cardinal outfielder on the helmet. But Van Slyke passed Clark near second base and Clark was subsequently trapped in a rundown.