HOUSTON – When Mike Cameron noticed that the Mets’ lineup card was posted yesterday morning, he took a quick glance, then did a double take. Making sure that really was his name in the sixth spot, he said, “Okay,” smiled, and stretched his arms.

So maybe it wasn’t just a coincidence that a few hours later, shortly after the trade deadline passed, he led off the eighth inning with a double off the wall and turned it into the pivotal go-ahead run in a 9-4 victory that ended the Houston Astros’ seven-game winning streak.

Cameron, the Mets’ most prominent player mentioned in trade talks, insisted afterward that his focus was strictly on baseball, but the Mets sure played like a relaxed team – not one going into the finale of a seven-game road trip having won just once, plus facing the looming threat of a roster shake-up to add Manny Ramirez or Danys Baez.

The Mets gave Astros starter Roy Oswalt his worst pounding at home since opening day, then still had to get a bloop single from seldom-starter Ramon Castro to take their first lead. Once ahead, they added four more runs in the ninth, the same amount they’d scored, total, over the previous three games. New York finished with a season-high 17 hits.

“I think it’s all coincidental,” manager Willie Randolph said. “That’s just the way it falls sometimes.”

Houston lost for only the second time in 15 games. Still, the Astros went 22-7 in July for their most wins and highest winning percentage ever in the month.

Oswalt struggled over six innings, later blaming a dead arm, but left with a 4-3 lead thanks to a career-best three hits and three RBI from Eric Bruntlett. The bullpen blew it, giving up six runs over the last three innings. Dan Wheeler (1-3) allowed the deciding run, then Russ Springer gave up four more in the ninth without retiring a batter.

Cameron was 3-for-5 with an RBI and two runs scored.

The game was therapeutic for several other Mets, too. Carlos Beltran, booed all four games by an Astros series-record crowd of 172,835, was 3-for-4 with a double, an RBI, and a stolen base. Doug Mientkiewicz, making his first start since being ejected Wednesday night, also went 3-for-5. Cliff Floyd had two hits, including an RBI single in the seventh that tied it at four.

Floyd missed a three-run homer by inches on the first pitch he saw from Oswalt, then ended up lining into an inning-ending double play. Leading off the fourth, he hit his 24th homer for the Mets’ first run.

Aaron Heilman (4-3) pitched one scoreless inning for the victory. Roberto Hernandez protected it in the eighth and closer Braden Looper pitched the ninth, even though the big rally in the top of the inning prevented it from being a save situation. Houston loaded the bases with two out on a hit batter, an infield single, and a walk, but Adam Everett fouled out to end it.