Mike Schmidt hit his second home run of the game with one out in the 11th inning yesterday in Houston to give the Philadelphia Phillies a 5-4 victory over the Astros.

Schmidt, who hit a three-run homer off starter Bob Knepper in the sixth inning, drove a pitch from Houston relief ace Dave Smith (1-6) over the left field wall for his sixth game-winning RBI of the season. It was his 19th homer of the season and the 477th of his career.

"Home runs are hard to come by here, but I shot straight today," Schmidt said. "I got that last home run off a good pitcher, too."

Steve Bedrosian (6-3) was the winner, pitching three innings of one-hit relief.

Schmidt's three-run homer in the sixth put the Phillies ahead, 4-1, against Knepper, who failed for the eighth time to achieve his 11th victory of the season. Schmidt's second homer gave him a league-leading 66 runs batted in, one ahead of New York's Gary Carter.

The Astros had tied the game at 4-4 with three runs in the bottom of the seventh. Houston's Glenn Davis hit his 20th homer, tops in the NL, in the fourth.

Giants 11, Pirates 4: Reserve first baseman Harry Spilman drove in four runs with a double and a three-run homer and Mike LaCoss (9-3) held visiting Pittsburgh to five hits in seven innings as San Francisco took over sole possession of first place in the NL West.

The Giants' victory and Houston's loss to Philadelphia put them one game ahead of the Astros. At 48-40, the Giants have undisputed possession of first place at the all-star break for the first time since 1978, when they finished third.

"We looked up at the scoreboard and saw that Houston lost," said third baseman Chris Brown, who raised his average to .338 with three hits. "Everyone felt an emotional high."

Mets 2, Braves 0: In New York, Ron Darling scattered nine hits for his first shutout of the season and center fielder Len Dykstra tripled, homered and threw out a runner at the plate as the Mets completed a four-game sweep of Atlanta.

Atlanta, which has lost nine of 10, was outscored, 28-2, during the series.

Darling (9-2), after three straight no-decisions, struck out seven and walked three. He allowed at least one hit in each of the first seven innings, four by Ken Oberkfell. The Braves left 10 men on base.

Doyle Alexander (1-1), who retired 14 in a row before Dykstra's homer in the sixth inning, allowed just four hits, struck out five and walked none in going the distance.

At the all-star break, the Mets have a 13-game lead over second-place Montreal in the NL East, their largest of the season.

Padres 13, Cardinals 6: Marvell Wynne had three hits and drove in three runs, and Steve Garvey had two hits during a seven-run fourth inning, as San Diego routed visiting St. Louis.

The Padres had only four hits in the fourth to go along with two walks, a hit batsman and two St. Louis errors.

LaMarr Hoyt (5-4) went the first six innings, allowing three earned runs, for his third straight victory.

Dodgers 4, Cubs 3: Alex Trevino's two-run double off the glove of Chicago left fielder Jerry Mumphrey with two out in the bottom of the ninth inning won for Los Angeles. It was the first time in 34 games this season the Dodgers have won a game in which they trailed after six innings.

Steve Sax started the winning rally with a leadoff single off reliever Lee Smith (6-7) and stole second. Ken Landreaux walked, but Mike Marshall grounded into a double play as Sax took third.

Len Matuszek walked before Trevino hit a 3-2 pitch toward the left field corner. Mumphrey chased the drive to the wall and appeared to have it in range, but the ball glanced off his glove as Sax and Matuszek scored.

Reds-Expos suspended: Kurt Stillwell singled home a sixth-inning run to give Cincinnati a 3-2 lead in Montreal in a game that was suspended by rain with one out in the top of the sixth.

The game will be resumed July 24 in Cincinnati before the next scheduled meeting of the two teams. The Expos will be the home team for the completion of the suspended contest. Yesterday was Cincinnati's last scheduled visit to Montreal this season.

The game was suspended after a wait of 1 hour 20 minutes.