It was business as usual for right-hander Rick Mahler, who is making a habit of pitching shutouts on opening nights.

Mahler allowed five hits and Dale Murphy hit a two-run homer to lead the Braves to a 6-0 victory over the Montreal Expos last night in Atlanta in an opener for both clubs.

It was the second straight year Mahler had a shutout in the opener. He blanked the Philadelphia Phillies, 6-0, last season and held the San Diego Padres scoreless in the Braves 1982 opener.

Murphy's homer came off loser Bryn Smith in the seventh inning and sailed over the right-field fence. He drove in Claudell Washington, who reached base on a single. Washington also knocked in a run with a sacrifice fly in the eighth.

The Braves had managed only one hit -- a first-inning double by Murphy -- before breaking a scoreless tie in the sixth inning and giving Chuck Tanner a victory in his debut as the Atlanta manager.

*Cardinals 2, Cubs 1: John Tudor pitched a five-hitter and Andy Van Slyke drove in two runs on one of two of the team's hits to lead the Cardinals to a season-opening victory over Chicago in St. Louis.

Tudor, who allowed a single in the first and sixth innings and two singles in the seventh, walked one in going the distance before a sellout Busch Stadium crowd of 48,672 -- the largest opening-day attendance in St. Louis history. The left-hander, who won 20 of his last 21 decisions last season, struck out one.

*Giants 8, Astros 3: Pinch hitter Candy Maldonado hit a three-run triple in the seventh inning and rookie Will Clark homered in his first big league at bat to lead San Francisco in Houston.

Maldonado hit the second pitch by reliever Jeff Calhoun down the right-field line to score Chris Brown, Bob Brenly and Brad Gulden, who were put on base by Houston starter Nolan Ryan.

Clark became the 53rd player in major league history to hit a home run in his first major league at bat. "When he hit home plate, he stopped to enjoy that moment," said Giants Manager Roger Craig. "He'll remember it the rest of his life."

*Padres 1, Dodgers 0: Dave Dravecky pitched a three-hitter and Terry Kennedy drove in the lone run with an infield hit in the third inning to lead San Diego in Los Angeles.

It was the sixth career shutout for the left-handed Dravecky.