Pedro Martinez took an early shower. It had nothing to do with the Arizona Diamondbacks.

Martinez pitched eight sharp innings and got a customary home run from Carlos Beltran as the Mets defeated Arizona 6-1 last night.

In the first inning, Martinez was pitching to Luis Gonzalez when the Shea Stadium infield sprinkler system went off, shooting water everywhere. Some pitchers might have been annoyed. Martinez was amused.

“I just got wet,” he said, laughing it off. “Water is a blessing.”

On a chilly June night, Martinez reacted like a kid playing in a pool in the middle of summer.

“I made it fun,” he said. “It was fun.”

So was beating out a slow roller down the third-base line, his first hit since September 4, 1997, with Montreal. It came in the middle of a three-run Mets rally in the sixth inning – and with Martinez throwing an airtight game, it just about finished off the Diamondbacks.

Martinez said he used the Diamondbacks’ approach against them.

“They came out aggressive,” he said. “I took advantage of their aggressiveness and spotted the fastball early in the count. I could reach for a power pitch when I needed it. I get a lot of grounders, especially if a team is aggressive.”

And a lot of strikeouts, too. Martinez struck out nine, increasing his NL-leading total to 92. He also got his regular home run from Beltran, who has hit seven this year, all with Martinez pitching.

“It’s been funny,” Beltran said. “But I want to hit them with someone else pitching. This means I hit them every five days. I want to hit them more often.”

Cliff Floyd, who batted .395 during a 20-game hitting streak from April 8 to May 4 but hit just .202 last month, had a pair of doubles against Shawn Estes (4-4), driving in one run and scoring another. After Arizona’s Tony Clark tagged Martinez for his sixth home run of the season in the second inning, the Mets took the lead in the fourth.

Beltran tied the score with a shot over the center-field fence, the deepest part of Shea Stadium. After Mike Piazza followed with a walk, Floyd doubled into the right-field corner. Piazza scored with a headfirst slide and Floyd reached third on a throwing error by second baseman Craig Counsell. Then Estes threw a wild pitch, allowing Floyd to score.

In the sixth, David Wright reached on Counsell’s third error of the game. He raced to third on a single by Chris Woodward and both runners scored on a double by Kaz Matsui.

Martinez beat out a roller down the third-base line, then Jose Reyes singled off Estes’ glove, allowing Matsui to score. That gave the Mets a 6-1 lead, a comfortable cushion for Martinez, who walked none and won his fourth straight decision. Martinez retired 13 straight batters from the third to the seventh.

Also yesterday, Mets relievers Felix Heredia and Bartolome Fortunato had surgery. Both are expected to miss the rest of the season.