Gonzalez hit an RBI double in the 14th inning, sending the Padres to a 5-4 victory over the Colorado Rockies on Saturday in the first extra-inning game for both teams this season.
San Diego stranded 13 runners in all, including 10 from the eighth inning on before finally pushing across the winner.
"We had some opportunities late and we just couldn't get the big knock," manager Bud Black said. "But the pitching held us together and finally we broke through."
David Eckstein, hitless in six previous at-bats, began the 14th with a bloop single off Manuel Corpas (0-1), the Rockies' seventh pitcher. Gonzalez followed with a double that rolled to the right-field wall, allowing Eckstein to come all the way around.
"He threw a sinker in on the first pitch," Gonzalez said. "I said, 'I'm going to look for that fastball in on the next one' because they'd been pitching me in all day. He threw it and I was able to turn on it."
While his double drove in the decisive run, Gonzalez said keeping the Rockies' powerful lineup at bay in hitter-friendly Coors Field made the difference, especially the pitching of reliever Tim Stauffer (1-0), who threw three scoreless innings in a game that lasted 4 hours, 27 minutes.
"That was pretty amazing for him, to throw zero after zero. That's the reason we won," Gonzalez said.
Iannetta homered in the third.
"We made plays in the field and got some good work from our bullpen," Stewart said. "I don't know what happened with our offense. It was one of those nights where we couldn't get a hit [late], let alone a clutch hit."
The Rockies had nine hits but only two in the final eight innings.
"We didn't do much to win the game," manager Jim Tracy said. "Our bullpen and our defense kept us in it, but our offense did little."
Hawpe's first homer of the season in the fourth pulled the Rockies within a run. With two outs in the sixth, he hit another solo shot off Mat Latos, tying it at 4 with his second career multihomer game.
Colorado starter Jason Hammel had a 2-0 lead until a 38-pitch fourth inning when the Padres scored four runs. Gonzalez had a one-out single, Kyle Banks was hit by a pitch and Chase Headley walked ahead of Will Venable's bases-loaded triple. Venable scored on Everth Cabrera's two-out double.
Latos allowed four runs and seven hits in six innings. Hammel gave up four runs and six hits in seven innings.
The Rockies reassigned LHP Joe Beimel from extended spring training to their Triple-A club in Colorado Springs to get back into pitching shape. The reliever was signed to a minor league contract on March 23. ... Though he was thrown out trying to stretch the first of three singles to a double in the second, Headley remains the only Padres player with a hit in each of the team's first five games. ... Hawpe's only other multihomer game came May 16, 2007, when he connected twice off Arizona's Brandon Webb at Coors Field. ... Hammel has a no-decision in each of his five career starts against San Diego.