Roger Mason pitched a three-hitter and Chili Davis hit two home runs to give the Giants their fifth straight victory, a 5-1 decision over the Los Angeles Dodgers last night in San Francisco.

Mason (1-1) retired the last 14 batters in a row. He lost his shutout when Ken Landreaux homered with one out in the fourth inning.

Davis connected for his first homer leading off the second. The Giants added three runs in the fourth. Jeff Leonard singled and Davis followed with a homer. Rob Thompson singled and scored on Jose Uribe's double.

*Mets 6, Pirates 5: Tim Teufel doubled home the tying run and scored the winner on Gary Carter's single in the ninth inning, rallying New York at home. It was the Mets' fourth straight victory and ended Pittsburgh's five-game winning streak.

Len Dykstra led off the ninth with a single off Pat Clements (0-1) and Kevin Mitchell sacrificed. Teufel then doubled down the right field line to score Dykstra. Keith Hernandez walked and Jim Winn relieved Clements. Carter singled down the left field line for his third game-winning RBI this season.

Pittsburgh took a 5-4 lead in the top of the inning when Joe Orsulak's bunt single brought in Lee Mazzilli from third base with two out.

Trailing by 4-2 in the eighth, the Mets tied the score as George Foster walked and Ray Knight homered.

The Pirates' Johnny Ray, who is batting .461 and has a nine-game hitting streak, had three singles.

*Braves 8, Astros 2: Glenn Hubbard and Bob Horner homered to lead Atlanta at home. The Braves' Joe Johnson pitched an eight-hitter.

Loser Nolan Ryan (2-2) was knocked out in the fourth inning. He allowed six extra-base hits.

"If I had to rate all the ballparks in the National League, this one Atlanta-Fulton County Stadium would be among my least favorite," Ryan said. "I can't recall any outstanding game I've pitched here."

With one out in the second, Ryan gave up a single to Ken Oberkfell and hit Bruce Benedict with a pitch. Hubbard then sent a drive over the fence in left field. Dale Murphy opened the Braves' third with a triple and scored on Horner's homer.