The right-hander, called up from Triple-A a day earlier, didn't get the decision but kept the Giants in the game as they beat the Padres 3-2 Friday night.
Todd Linden scored the go-ahead run on Khalil Greene's throwing error with one out in the eighth inning to give San Francisco its fourth straight victory.
Correia grew up a Padres fan during the Tony Gwynn era and was roomates in college with the oldest son of San Diego manager Bruce Bochy.
"It was a little more important for me to pitch well here than other spots," said Correia, 24, who was making his first big-league start of 2005.
Correia allowed two runs in the first inning, including Mark Sweeney's solo homer, but then settled down.
"At that point all I could hope for was to pull together and not give up any more runs," said Correia, who made his second career start against the Padres. "It's easy to give up at that point."
Correia left after five innings with the score tied at 2. He allowed six hits, walked three and struck out two.
"He looked a little nervous to me, but he more or less settled down," manager Felipe Alou said. "He's a tough kid. He's got good stuff. He gave us five innings of opportunity to stay in the game."
The victory in the series opener against the NL West-leading Padres came after the Giants swept three games at Arizona, which is tied for second with Los Angeles in baseball's weakest division. The Giants are fourth, eight games behind the Padres, who have lost three of four.
Linden, pinch-hitting for pitcher Jason Christiansen leading off the eighth, reached when he was hit by a pitch by Rudy Seanez, then was sacrificed by Alex Sanchez. Greene made a diving stop of Omar Vizquel's grounder behind second base that went for an infield single, then scrambled up and hurriedly threw wide of first, allowing Linden to score an unearned run.
Christiansen (5-1) pitched a perfect seventh for the win. Tyler Walker got five outs for his 12th save in 14 chances. Seanez (4-1) took the loss.
Padres ace Jake Peavy struck out nine in six innings, but was lifted for a pinch-hitter in the bottom of the sixth with the score tied at 2. He allowed two runs and four hits, and walked just one.
Peavy was frustrated about being pinch-hit for.
"I'm upset about the whole night," he said. "I know you have to do that, but it didn't work out. There's no way we should have lost that game.
"To go six innings and get pulled, there are not more frustrating nights than this."
San Francisco tied it with two outs in the fourth when Pedro Feliz's bloop single fell in between Greene and center fielder Xavier Nady to score Moises Alou. Alou hit a leadoff single and advanced on Ray Durham's groundout.
San Diego failed to score in the sixth after loading the bases. Sean Burroughs and Nady hit consecutive singles and advanced on Greene's sacrifice. Rookie Paul McAnulty, pinch-hitting for Peavy, was intentionally walked before Damian Jackson hit into a 1-2-3 double play.
Bochy said it was a tough decision to lift Peavy.
"He had an inning or two left," Bochy said. "I thought we needed to get some runs there.
"Our execution was not very good tonight," Bochy added. "Usually in a close game, that comes back to haunt you."
Peavy had an adventuresome first inning, when the Giants scored a run on J.T. Snow's groundout. Peavy had to dodge Sanchez's shattered bat on an infield single leading off the game. Sanchez stole second, took third on Vizquel's groundout and scored on Snow's grounder to second. First baseman Sweeney dived for the ball and missed, leaving Peavy to cover first. He fielded the throw and dived at the bag, tagging it with his glove.
San Diego took a 2-1 lead in the bottom of the first. Sweeney homered to right on a 2-2 pitch with one out, his fifth. With two outs and the bases loaded, Nady lined a single off first base that bounced high in the air, allowing him to reach and Ryan Klesko to score.
Greene grounded out to end the threat.