SAN DIEGO -- Right-hander Bartolo Colon hit the first home run of his major league career and held the San Diego Padres to three runs in 6 2/3 innings Saturday night to lead the New York Mets to a 6-3 win at Petco Park that snapped a two-game losing streak.

All six Mets runs came on homers.

Yoenis Cespedes opened the game with a first-inning, two-run shot off Padres starter and loser James Shields (1-5).

Colon hit a two-run homer off Shields in the bottom of the second that gave the Mets a 4-0 lead. And David Wright and Michael Conforto hit back-to-back homers off reliever Carlos Villanueva with one out in the ninth.

Colon the pitcher allowed three runs -- on a three-run homer by Jon Jay -- on six hits and a walk with five strikeouts to pick up the win and improve to 3-1. Closer Jeurys Familia posted his ninth save of the year.

Colon's historic homer came on the 226th at-bat of his career. He hit a 1-and-1 fastball from Shields in the bottom of the second 358 feet to left.

Going into the at-bat, Colon was a .089 career hitter with two doubles and nine RBIs. He also tied his career best for a game with the two RBIs.

Colon became the second oldest Mets player to hit a home run. Julio Franco was 48 when he last homered as a Met on May 4, 2007. Colon also became the oldest player in major league history at the time of his first homer.

Colon's homer was the second of the game off Shields and upped the Mets' lead to 4-0.

New York took a 2-0 lead in the fourth when Wright drew a one-out walk and Cespedes hit a 370-foot homer to left. The homer was Cespedes' 10th of the season and raised his RBI total to 29.

Catcher Kevin Plawecki set the stage for Colon with a two-out double in the fourth. As Colon trotted slowly around the bases, the rest of the Mets players and coaches exited the dugout through a tunnel leading back to the clubhouse.

Colon didn't have long to enjoy his homer, however.

Padres center fielder Jon Jay brought the Padres back within a run with a three-run homer off Colon in the third.

Derek Norris opened the third with a single and reached second on the first of two Shields singles. Jay then lined a 1-and-2 fastball from Shields 417 feet to right center.

Shields, who tied for the major league lead with 33 homers allowed last season, had gone three straight starts without giving up a homer. He gave up four runs, five hits and five walks while striking out eight in six innings.

Going into Saturday night, Padres starting pitchers had a 1.64 ERA.

The Padres, who already have three infielders on the disabled list, apparently lost a fourth Saturday night at a most inopportune time.

Norris opened the inning with a single off Colon. Second baseman Jemile Weeks placed a perfect bunt and apparently was going to beat it out for a single when he fell to the ground short of first base with an apparent right hamstring injury.

With Norris at second, Colon struck out pinch-hitter Jabari Blash and left-handed reliever Jerry Blevins came on to strike out Jay and end the threat.

NOTES: C Travis d'Arnaud felt discomfort when he threw at the Mets' year-round Florida base for the first time since going on the disabled list April 28 with a rotator cuff strain. He will continue to take batting practice but stop throwing until a future evaluation. ... Padres 3B Yangervis Solarte (hamstring) and INF Alexi Amarista (hamstring) will travel to the Padres' year-round training base Sunday to increase their rehab activity. Both should be on a minor league rehab assignment by next weekend. ... Padres pitchers Matt Thornton (left Achilles strain) and Jon Edwards (forearm strain) are also headed to the Padres' extended spring training facility in Arizona on Sunday afternoon to start facing live hitters as the next stage before rehab assignments.