OAKLAND, Calif. – Led by two struggling stars, the Mets broke out of their offensive funk.

Mike Piazza ended the longest home run drought of his career, Carlos Beltran hit a three-run shot, and New York avoided a three-game sweep with a 9-6 victory over the Oakland Athletics yesterday.

Beltran’s eighth homer, a long drive to right in the fifth that put the Mets ahead, was his first for New York in a game not started by Pedro Martinez.

Piazza hadn’t homered since May 9, a stretch of 98 at-bats without going deep, according to the Elias Sports Bureau.

“It’s been a while. I felt like I’ve been swinging the bat better the last 30 or 40 at-bats or so, but I’m still not driving the ball as well as I can,” Piazza said. “Carlos came up with a big home run. That kind of got us going.”

Willie Randolph is a man of intuition, and everything told the Mets’ manager that a couple tweaks to the lineup might get his team’s offense back on track. He moved David Wright to the second spot for the first time this season, and Wright delivered an RBI single before Beltran’s homer.

“I’m a vibe person,” Randolph said. “You might think I’m crazy, but when I get a feeling about something, it usually works.”

Ramon Castro had a two-run double and matched his career high with three RBI, and Kris Benson (5-2) pitched six solid innings to win his second straight decision despite giving up two home runs in a game played in a steady drizzle.

This was a key victory for the Mets, who have been struggling to score and needed a lift as they concluded the first series of their season-long 12-game road trip. They had one hit through the first four innings, then the first six batters got hits in the fifth.

The Mets had lost three in a row and six of seven and hadn’t scored more than three runs in any of the defeats. The Mets scored more runs in their seven-run fifth than they had in their previous three games.

Braden Looper pitched the ninth for his 13th save in 15 chances, getting Bobby Crosby to ground into a game-ending double play. Jason Kendall slid hard into second baseman Kaz Matsui, who stayed down briefly before limping off the field.

Matsui had ice on his left knee afterward, but said he would try to play today. Neither he nor Randolph accused Kendall of a dirty slide.

Nick Swisher hit a two-run homer, and Mark Kotsay also connected for the A’s, who had won three straight and nine of 10 at home. Every A’s starter had a hit.

Oakland made it interesting with three runs in the eighth off Danny Graves. Bobby Kielty and Swisher each had an RBI single, and Keith Ginter doubled in a run.

After Swisher’s second-inning homer, Benson allowed back-to-back singles before retiring 13 of his final 16 batters.

Beltran’s homer chased A’s starter Ryan Glynn (0-3), and reliever Juan Cruz gave up consecutive singles to Cliff Floyd and Piazza. Castro hit his two-run double three batters later.

Piazza led off the seventh with a shot to left-center, giving him 385 homers to tie Dwight Evans for 47th place on the career list.

Brian Daubach started at first base for the Mets, drew three walks, and scored twice, one day after being called up from Triple-A Norfolk when Miguel Cairo went on the disabled list with a hamstring injury. Daubach was drafted by the Mets in the 17th round in 1990, but this was his first big league game for the club.

“It’s about time,” he said, still carrying a Norfolk Tides duffel bag. “I signed with the Mets and it took me 15 years.”

Mets outfielder Mike Cameron was given another day off to allow the swelling in his right knee to subside. Cameron hopes to play sometime this weekend against his former team in Seattle.

Also yesterday, the Mets signed veteran catcher Benito Santiago to a minor league contract.