Steve Garvey, the National League record-holder for consecutive games played, dislocated his left thumb in San Diego last night in the first game of a doubleheader against the Atlanta Braves, bringing an end to his streak at 1,207 games.

Garvey, who was taken to Scripps Clinic in La Jolla, sustained the injury in the first inning when he attempted to score from third base on a errant pitch. A subdued Garvey left the emergency room with a elbow-length cast.

Dr. Paul Hirshman, an orthopedic surgeon at the clinic, said Garvey will be sidelined at least three weeks.

"Once I slid and was tagged, I felt the thumb go numb," Garvey said in the lobby after coming out of the emergency room. "I knew there was something wrong."

Garvey, 34, ranked third on the all-time consecutive game-playing list behind Lou Gehrig with 2,130 and Everett Scott with 1,307.

"The injury was a disappointment," he said. "I'm disappointed that I can't help my team at a time that's very important. Baseball is a team sport. It's a very hollow feeling to know that I can't contribute. It's as low as I've felt in many, many years."

Garvey signed a five-year, $6.6 million contract as a free agent last December after starring for the Los Angeles Dodgers for 12 years. The veteran first baseman broke the previous NL record of 1,117 games held by Billy Williams of the Chicago Cubs on April 16 in his first return to Dodger Stadium as a Padre.

Garvey said he always knew that an injury might end his streak. "But all in all, if I was to get injured, I wanted it to happen when I was playing aggressively. I wanted to get that run," he said.

Garvey had not missed a game since Sept. 2, 1975 when the Dodgers met the San Francisco Giants.

Garvey sustained the injury in the first inning of the opening game when he jammed his thumb attempting to score from third base on a wild pitch by Braves right-hander Pascual Perez. Kurt Bevacqua replaced Garvey at first base.

Garvey, batting .292, singled Alan Wiggins to second base. Ruppert Jones singled in Wiggins with Garvey going to third. Perez then threw his errant pitch and Garvey ran for the plate. He was out easily as he tried to beat the throw from catcher Bruce Benedict to Perez, who was covering the plate.

Pirates 2, Mets 1: Tony Pena's two-out homer in the seventh inning and the combined four-hit pitching of John Candelaria and Cecilio Guante helped NL East-leading Pittsburgh defeat New York and increase its record to 19-5 since the All-Star break.

Pena broke a 1-1 tie with his fifth homer of the season on a 1-0 pitch into the right field bullpen at Shea Stadium.

Candelaria (10-6, 7-0 in his last 11 appearances), recorded seven strikeouts and no walks, and had retired 19 in a row before Brian Giles singled with two out in the seventh inning. Guante relieved and allowed no hits to record his fourth save.

Tom Seaver (6-11) suffered his fifth defeat in his last seven starts, despite allowing only four hits in eight innings.

Expos 7, Cardinals 2: Al Oliver knocked in two runs to highlight a five-run fifth inning that helped host Montreal end St. Louis' six-game winning streak.

Bryn Smith (2-4), making his first start of the season, allowed eight hits, walked two and struck out four in going the distance. Used almost exclusively as a reliever, Smith's last start was in September, 1982.

The Expos opened the scoring in the fourth inning when Andre Dawson broke a string of 21 2/3 shutout innings pitched by Neil Allen (7-9) by belting his 23rd homer of the season.

Phillies 3, Cubs 2: Bo Diaz singled home Mike Schmidt from second base with one out in the ninth inning to give Philadelphia the victory over visiting Chicago.

Schmidt led off with a single off Lee Smith (4-6) and went to second on a sacrifice by Joe Lefebvre. After Garry Maddox received an intentional walk, Diaz hit a single down the left field line to make a winner of Al Holland (5-0).

The Phillies tied the score at 2 with an unearned run in the eighth. Starter Dickie Noles, who had not allowed a hit since the second, allowed a leadoff ground-rule double to Ivan DeJesus. Greg Gross sacrificed DeJesus to third and was safe at first when Ryne Sandberg dropped the throw for an error. DeJesus then scored on Pete Rose's sacrifice fly off Smith.

Giants 5, Dodgers 2: Bob Brenly sent host San Francisco ahead with a pinch-hit RBI single in a four-run seventh inning as the Giants defeated error-plagued Los Angeles.

Winner Mike Krukow (6-6) gave up four hits and struck out nine in 8 2/3 innings for his first victory since June 24. Reliever Greg Minton recorded the last out.

With the score tied at 1, Jeff Leonard led off the bottom of the seventh with a grounder to third base, and third baseman Pedro Guerrero dropped the ball for his second error. Tom O'Malley singled, sending Leonard to third.

Astros 4, Reds 1: Mike Madden, making only his second major-league start, combined with Dave Smith on a six-hitter and Ray Knight hit a home run as Houston ended a five-game losing streak over visiting Cincinnati.

Madden (4-0) pitched seven innings and allowed six hits, walked one and struck out two. Smith earned his fourth save of the year.