Keith Hernandez had five hits and drove in three runs and Gary Carter and George Foster each hit a two-run homer to lead a 20-hit New York offense as the Mets beat the Expos, 14-7, last night in Montreal.

Darryl Strawberry hit his 16th home run, and Wally Backman contributed two hits and three RBI as the Mets worked on four Montreal pitchers. Rick Aguilera (5-3) went five innings, giving up all seven Montreal runs on nine hits. Terry Leach finished the game to earn his first save.

The Mets got off to a quick start against Expos starter Joe Hesketh (9-5) as Hernandez singled home Tom Paciorek in the first inning. Paciorek had drawn a one-out walk and stolen second.

The lead proved short-lived as Montreal scored three times in its half of the first. Tim Raines led off with a walk and scored on Vance Law's double. Hubie Brooks followed with a run-scoring double, moved to third on the first of Terry Francona's four hits and scored on Tim Wallach's sacrifice fly.

The Mets came back with a five-run second, highlighted by Hernandez's two-run double and Carter's 14th home run. New York added a pair of runs against Bert Roberge in the third and scored two in the fourth on Foster's 16th homer.