Dave Johnson hit his second pinch-hit grand slam of the season into the left-field corner grandstand with none out in the bottom of the ninth yesterday and the Philadelphia Phillies beat the Los Angeles Dodgers, 5-1.

Garry Maddox opened the ninth with a single and reached third when reliever Terry Forster threw wild to first on an attempted pickoff. Greg Luzinski and pinch hitter Jerry Martin were intentionally walked to load the bases and Johnson became the first major leaguer to hit two grand-slam homers as a pinch-hitter in one season.

Forster had allowed only one earned run in his previous 11 appearances, totaling 17 1/3 innings. He had struck out 16 batters in that stretch.

The Phillies opened the scoring in the fifth when Bob Boone lined his fifth home run of the season off the base of the left-field foul pole.

Los Angeles, which wasted a Lee Lacy double in the second and a Steve Garvey triple in the fourth, tied with an unearned run in the sixth. Bill North walked and took second on a wild pickoff attempt by Larry Christensen. North went to third on Bill Russel's sacrifice and scored on Reggie Smith's sacrifice fly.

Starter Don Sutton, who became the all-time Dodger leader in innings pitched in the first inning, struck out three to tie Lefty Grove for 23rd place on the all-time strikeout list with 2,226. Don Drysdale had been the Dodgers' innings-pitched leader with 3,112.