Chris Speier drove in a team-record eight runs with a bases-loaded triple, a three-run homer and a single to back the five-hit pitching of Bill Gullickson as Montreal defeated Philadelphia.
The eight RBI broke the Expos' record of seven, shared by four players, most recently Larry Parrish in 1980.
Speier set the record with his seventh homer of the season, giving Montreal a 10-4 lead in the seventh.
"I didn't think the ball was going out," said Speier, who emerged from the dugout to acknowledge a standing ovation from the crowd of 18,123 at Olympic Stadium.
"It's the first time I can remember receiving that type of ovation for my hitting," he said. "I've received ovations in the past for my fielding.
"I don't think I did that (drive in eight runs) even in Little League," Speier said.
"I'm not big on statistics, but that's probably the best offensive night I've ever had. Coming from a singles hitter, I guess it's not too bad."
The Expos had scored three runs in the second against Philadelphia starter Dick Ruthven (11-11).
Gary Carter and Tim Wallach opened the inning with singles and Warren Cromartie walked to load the bases with none out. Speier then grounded a triple that rolled all the way to the center field wall allowing all three runners to score.