SAN FRANCISCO, AUG. 30 -- Gary Carter's 11th career grand slam capped a five-run first inning as the New York Mets beat the San Francisco Giants, 5-3, today. Carter's home run, his 18th of the season, ruined the first Giants home appearance by right-hander Rick Reuschel (9-7), recently acquired from Pittsburgh.

"I was fortunate to get the pitch I was looking for," Carter said of the first-pitch curveball that he hit over the left field screen. Carter leads all active National League players in grand slams.

New York's Rick Aguilera (6-2) made only his second start since coming off the disabled list after suffering strained ligaments in his right elbow. He gave up three runs on nine hits in 8 2/3 innings.

Aguilera entered the ninth inning with a 5-1 lead but gave up home runs to Will Clark, his 27th, and Bob Brenly, his 16th. Roger McDowell got the last out for his 21st save.

Len Dykstra led off for the Mets in the first with a triple and scored on Dave Magadan's single. Keith Hernandez's single and Darryl Strawberry's walk loaded the bases for Carter.

New York won the season series from the Giants, 9-3, the team's most victories against San Francisco since divisional play began in 1969.

Expos 5, Dodgers 4:

Pinch hitter Wallace Johnson drove in the tying and winning runs with a two-out double in the ninth inning as Montreal won in Los Angeles for its fifth straight victory.

Trailing by 4-2, the Expos loaded the bases for the third time against Fernando Valenzuela (11-12) on Reid Nichols' single, a one-out walk to Vance Law and Mike Fitzgerald's bunt single.

Casey Candaele hit a sacrifice fly off reliever Tim Crews and Johnson, batting for winning pitcher Jeff Parrett (5-5), doubled to right, scoring Law and pinch runner Pascual Perez. Johnson has 15 hits in 52 pinch hitting appearances and 11 RBI.

Cubs 3, Reds 1:

Andre Dawson hit a two-run homer and a run-scoring single as Chicago won in Cincinnati, handing the third-place Reds their eighth loss in their last nine games. Ed Lynch (2-8) pitched five shutout innings, allowing one hit and ending a personal eight-game losing streak.

Dawson hit his 43rd home run of the season in the sixth inning, giving him 115 RBI to surpass his career high of 113 set with the Montreal Expos in 1983. His hits spoiled an otherwise effective Reds debut for left-hander Dennis Rasmussen.

Reds Manager Pete Rose said yesterday he would not activate himself as a player in time for postseason play, but he did not rule out coming back either next year or next month, when major league rosters expand to 40 players.

Pirates 7, Astros 0:

Doug Drabek pitched a three-hitter for his first major league shutout and complete game and John Cangelosi hit a three-run homer, leading Pittsburgh, playing at Three Rivers Stadium, to its sixth straight victory.

Drabek (7-10) retired 10 consecutive batters at one point to win his fifth consecutive game as the Pirates completed a three-game sweep and extended Houston's losing streak to five games.

Cardinals 4, Braves 3:

Jose Oquendo capped a three-run ninth inning with a bases-loaded suicide squeeze bunt, giving St. Louis the win at home.

With Jack Clark breaking, Oquendo dropped the first delivery from reliever Gene Garber down the third base line, extending the Cardinals' winning streak to five games. Atlanta has lost four straight.

After the game, the Braves announced they had traded Garber, 39, to the Kansas City Royals for a player to be named. The right-hander had an 8-10 record this season with 10 saves and a 4.41 ERA.

The Cardinals dealt left-handed relief pitcher Pat Perry to Cincinnati for a player to be named. Perry was 4-2 with a 4.39 ERA and one save in 45 games.

Padres 6, Phillies 1:

Mark Grant pitched an eight-hitter for his first major league complete game and Chris Brown and Marvell Wynne homered as San Diego won at home.

Earlier, the Padres traded pitcher Storm Davis to the Oakland Athletics for two players to be named. He was acquired last October from Baltimore for catcher Terry Kennedy and pitcher Mark Williamson and was 2-7 with a 6.81 ERA.