George Foster made the kind of contribution to the New York Mets yesterday that they haven't seen too often since they acquired him four years ago from the Cincinnati Reds.

Foster hit two home runs off Jerry Reuss in the Mets' 8-4 victory over the Dodgers in Los Angeles, marking the 21st time in his career he has hit two or more homers in one game.

"When I'm swinging the bat well and hitting for power, I'm able to hit home runs in bunches," said Foster, whose last multiple-homer game came in September 1983. "I know it hasn't taken place since I've been with the Mets. But today was an indication that things are starting to change."

Relievers Randy Niemann (1-2) and Roger McDowell allowed four hits over the last 6 1/3 innings to secure the victory, ending the Mets' first two-game losing streak and the Dodgers' four-game winning streak.

The Mets got four consecutive hits off Reuss (2-2) in the first inning. One-out singles by Kevin Mitchell, Keith Hernandez and Gary Carter produced one run before Foster hit his third homer of the season.

Foster made it 5-0 in the third with a one-out drive over the left-center field fence.

*Expos 8, Padres 3: Hubie Brooks hit a grand slam and Tim Raines doubled twice during a seven-run first inning to help Montreal win in San Diego.

The Expos, who have won 12 of their last 15 games, bunched eight hits and two walks in the first inning. Starter Mark Thurmond (2-3) gave up five hits and six runs before he left without retiring a batter.

Raines led with a double, Mitch Webster singled and Andre Dawson walked, loading the bases.

Brooks hit Thurmond's 2-0 pitch into the left field seats for his 10th home run of the season, tops in the NL. It was the third career grand slam for Brooks, who leads the NL with 32 RBI, and was his third home run in three days against the Padres.

"This is about as hot as I've ever been," Brooks said. "I'm just swinging the bat good and I just want to keep up at a steady pace."

*Cubs 5, Astros 2: Reliever Guy Hoffman (1-1) allowed four hits in 5 1/3 innings to record his first victory since 1983, and Scott Sanderson notched the fourth game-winning RBI by a Cubs pitcher this season as Chicago won in Houston.

Hoffman (1-1) relieved Sanderson in the second inning. Sanderson suffered a bruised right knee after being hit by a pitch in the top of the inning. Hoffman walked two and struck out five. Lee Smith worked 2 1/3 innings to record his fifth save of the season. Bob Knepper (7-2) failed in his bid to become the major leagues' first eight-game winner.

*Reds 7, Pirates 3: Dave Parker's three-run homer helped Tom Browning get his first victory of the season as the Reds beat Pittsburgh in Cincinnati.

Browning (1-4) allowed six hits over six innings for his first victory since Sept. 28, when he beat Houston and became the first rookie 20-game winner in the major leagues in 31 years.

The left-hander walked four and struck out five, pitching out of bases-loaded threats in the first and third by retiring Tony Pena both times. Ron Robinson finished up for his second save, giving up Jim Morrison's seventh homer of the season.

*Giants 4, Phillies 1: Jeff Robinson allowed only one hit in 3 2/3 innings and the Giants took advantage of five Philadelphia errors to gain the victory in San Francisco.

Robinson entered with the bases loaded and one out in the sixth and induced Glenn Wilson to ground into a double play. He then struck out six over the next three innings to record his fourth save. Scott Garrelts (4-3) got the victory.

The Giants took a 3-0 lead in the fifth off starter Fred Toliver (0-1).

*Braves 5, Cardinals 2: Bob Horner hit a pair of two-run homers and Dale Murphy singled in the go-ahead run with two outs in the seventh inning as the Braves beat St. Louis in Atlanta.

It was Atlanta's fourth straight victory, its longest winning streak of the season. St. Louis lost for the fifth consecutive time.