The Phillies, in first place in the National League East Division by a fraction of a percentage point, fired Manager Pat Corrales and replaced him for the rest of the season with General Manager Paul Owens yesterday in Philadelphia.

In Owens' debut, the Phillies lost to Houston, 8-2, and fell a half-game behind St. Louis and into a tie with Pittsburgh at 43-43.

"When you see ball players hitting 40 points below where they've been hitting, something is wrong," Phillies President Bill Giles said at a news conference at Veterans Stadium.

"It's the job of the manager to motivate and get the players to play up to their capabilities. Whether it's the players' fault, Pat's fault or my fault, we have to find out.

"There is something wrong with this club, and Paul and I have kicked around the idea of making a change. We both felt he'd be the best person to run the club for the rest of the season. Next year, he'll return to his role in the front office."

Owens said Corrales, who signed a two-year contract extension last winter, was stunned. "I explained that it was a business situation, nothing personal. He wished us luck and said he was going home" to Pine Hill, N.J., Owens said.

Giles said the players' reaction to the change has been positive. But Pete Rose disagreed. "I can't ever remember a guy in first place being fired," Rose said.

In last night's game, Joe Niekro gave up seven hits as Houston won in Philadelphia.

"It was a bad managing job," Owens said jokingly.

Steve Carlton (9-11) lasted just 3 2/3 innings and took the loss but regained the all-time strikeout lead. Carlton struck out five to increase his career total to 3,587, four more than Houston's Nolan Ryan.