World series hero Mike Schmidt hit a three-run home run in the top of the first inning at Bush Stadium and Dick Ruthven made it stand up with a give-hitter as the Philadelphia Phillies thwarted St. Louis in the Cardinals' season opener yesterday, 5-2.

The Cards executed the first triple play of the season but could not extend their string of five straight opening-day successes.

Schmidt's homer, a towering drive over the left field wall, came after Pete Rose led off with a double and Manny Trillo walked off right-hander Bob Forsch.

Up 4-2, the Phils scored insurance in the eighth when reliever Jim Kaat mishandled a bunt by Bake McBride after singles by Rose -- his fifth hit in two games -- and Trillo. The same inning, the Cardinals pulled their first triple play since May 8, 1977. With the bases loaded, Gary Matthews hit a low line drive to shortstop Garry Templeton for the first out. Templeton, in case the ball should be ruled trapped, threw to catcher Darrell Porter, who relayed the ball to first baseman Keith Hernandez to double Schmidt for the second out. Hernandez threw to third baseman Ken Oberkfell, who tagged out McBride.

Ruthven allowed St. Louis' runs in the fourth inning, one coming in on a double by Keith Hernandez, the other as Porter grounded into a double play. Ruthven struck out five and walked none in pitching the complete game.

Larry Christenson, scheduled starter for the Phillies as the series continues Sunday, received a negative finding on X-rays of his right thumb, injured Thursday outside a St. Louis tavern. Police said Christenson also incurred a bloody nose when struck several times by an unidentified man.