Pinch hitter Mike Easler hit a grand slam home run to highlight a six-run seventh-inning yesterday in Atlanta and give the Pittsburgh Pirates a 6-2 victory over the faltering Braves. The loss was Atlanta's sixth in a row and dropped the Braves 3 1/2 games behind Los Angeles in the West Division.

The victory boosted the Pirates to a one-game lead over Philadelphia in the East Division.

Atlanta led, 2-0, before the Pirates rallied in the seventh against Phil Niekro and reliever Steve Bedrosian (8-8).

Marvell Wynne began the comeback with a walk, one of 12 issued by Braves pitchers, and scored on Bill Madlock's double, only the second Pittsburgh hit. Jason Thompson then walked and, one out later, Johnny Ray doubled, scoring Madlock. Tony Pena was walked intentionally to load the bases, bringing in Bedrosian. Pinch hitter Tom Orsulak struck out before Easler, batting for reliever Jim Bibby, hit the first pitch over the center field fence.

"He walked eight guys," Braves Manager Joe Torre said, explaining why he took out Niekro. "You can second guess me. That's okay. Niekro had good stuff but had thrown a lot of pitches and I felt it was time to get him and go with the best I had in my bullpen."

Niekro said he came to the park to win and "I was going to win. I just had a feeling.

"I walked a few and I was in and out of jams, but I cracked down when I had to, getting the outs and strikeouts. To me, I was pitching good."