ST. LOUIS (AP) _ Terry Francona's two-run single off third baseman Terry Pendleton's glove in the 10th inning gave the Montreal Expos a 6-5 victory Sunday over the St. Louis Cardinals and Joaquin Andujar.

Francona's hit kept Andujar, 19-7, from becoming the major leagues' first 20-game winner, and gave the victory to reliever Gary Lucas, 4-2.

Despite the loss, St. Louis remained in a tie for first place in the National League East with ther New York Mets, who lost 5-0 to the Pittsburgh Pirates. The Expos are now four games out of first place in the National League East.

Tim Raines led off the 10th inning with a double and Vance Law walked on four pitches. After Andre Dawson grounded out to advance the runners, Ken Dayley relieved and walked Hubie Brooks intentionally. Francona followed with his hit.

Despite giving up a bases-loaded walk to Pendleton, Jeff Reardon got the last two outs in the bottom of the 10th for his 31st save. He fanned Andy Van Slyke for the final out.

St. Louis jumped ahead 2-0 in the first, highlighted by Ozzie Smith's run- scoring single and Tito Landrum's RBI triple.

A double-play attempt that went awry in the second helped the Expos tie the score.

Tim Wallach, who had singled, barely was able to get back to first when Jack Clark was unable to scoop Landrum's throw out of the dirt after Herm Winningham flied to right field. Two pitches later, Sal Butera hit his second major-league homer.

The Expos jumped ahead 4-2 in the fourth on a triple by Law and a sacrifice fly by Dawson.

Landrum doubled home St. Louis' third run in the sixth and Tommy Herr hit his fourth homer in the bottom of the eighth to tie the game 4-4.