A seventh-inning throwing error by Philadelphia second baseman Juan Samuel on a potential double play ball allowed the tying and winning runs to score as the Chicago Cubs beat the Phillies today, 3-2.

The victory increased the Cubs' lead in the National League East to seven games over the New York Mets and reduced Chicago's magic number to 12.

The Phillies went into the seventh with a 2-0 lead and 40-year-old left-hander Jerry Koosman trying for his 33rd career shutout.

In the Cubs' seventh, Jody Davis drew a one-out walk and moved to second on a single by Larry Bowa. Pinch hitter Gary Woods blooped a single to right to load the bases and Koosman walked Bob Dernier to force Davis home.

Koosman (14-12) was replaced by Larry Andersen, who got Ryne Sandberg to ground to shortstop Ivan DeJesus. He threw to Samuel, but the relay sailed into the Phillies' dugout as Bowa and Woods scored. Sandberg was credited with one RBI on the play. The error was Samuel's 31st of the year.

"Everybody needs luck," the Cubs' manager, Jim Frey, said. "Early in the game, we didn't have any and look what happened. We didn't score a run." Frey said all baseball teams go through periods when luck is at a premium. "Who really knows what luck is?" he said. "It's all guesswork."

Phillies Manager Paul Owens said his club was snakebitten on the play. "It would have been a bang-bang play if it had worked. If you hold the ball, it would have been tied and who knows," he said.

"You still have to have a little bit of luck to win and I suppose we could debate all night whether Samuel's throw to first would have beaten Sandberg. But, from where I was sitting, I figured he had to try to make the attempt and he can't be faulted for that."

Sandberg believes he had the throw beaten. "The ball went behind me as I passed the bag," he said.

The Phillies broke a scoreless tie in the fifth. Glenn Wilson singled, advanced to second on a ground-out and held second when Steve Jeltz was credited with an infield single. Koosman moved the runners one base with a sacrifice bunt and Samuel was intentionally walked before Von Hayes drove a single up the middle, scoring two runs.

Tim Stoddard (9-5), who relieved starter Steve Trout in the sixth, was the winner. Lee Smith pitched the final two innings for his 31st save.

"Playing aggressively, and not believing in 'In God We Trust' will earn the Chicago Cubs the Eastern Division title," Bowa said. "While God has to smile on you, he is not smiling any more on the Chicago Cubs than on any other team."