Orel Hershiser pitched a four-hitter for his ninth victory without a loss at home this season and Pedro Guerrero had three hits, including his 32nd home run, as Los Angeles defeated Montreal.

Hershiser (14-3) struck out six, walked one and did not allow a runner past first base in his fifth shutout of the season. At home this season, the 26-year old Hershiser has yielded just 12 earned runs in 107 1/3 innings for an earned run average of 1.01.

Overall, Hershiser lowered his ERA to 2.18 and has pitched 15 straight scoreless innings. The shutout was the 20th for Los Angeles pitchers this season, tops in the major leagues.

The victory moved Los Angeles 7 1/2 games ahead of Cincinnati in the National League West.

The Dodgers took a 1-0 lead in the first inning when Guerrero singled home Ken Landreaux, who had singled and stolen second.

Guerrero led off the fourth with a single against Bryn Smith (15-5), who had won eight of his last nine decisions. Guerrero stole second, took third on a single by Bill Madlock and scored on Mike Scioscia's groundout. Madlock stole second and scored on a single by Len Matuszek.

Bill Laskey relieved Smith to start the sixth inning, and Guerrero drove Laskey's second pitch over the center field wall. Guerrero is just one home run short of the Los Angeles team record held by Steve Garvey in 1977. Guerrero had 32 homers in the 1982 and 1983 seasons.

"It has to go," Guerrero said of the record. "If I don't hit at least one home run in 33 games, I'm going to retire."