MLB

HIDEKI JUST GRAND

OAKLAND Hideki Matsui had a present for the Yankees on his 34th birthday last night that may or may not have legs.

With Andy Pettitte pitching very well, Matsui turned a sixth-inning one-run deficit into a three-run lead with a grand slam off Joe Blanton that lifted Pettitte and the Yankees to a much-needed 4-1 victory over the A’s at McAfee Coliseum that was witnessed by 28,658.

“He is the birthday boy; that’s what you are supposed to do on your birthday,” Joe Girardi said of Matsui’s seventh homer this year and his fifth slam in America.

Hours earlier, the Japanese media presented Matsui with a birthday cake he didn’t eat. While Matsui accepted birthday wishes in the clubhouse prior to the game, Pettitte didn’t know it was Matsui’s birthday until after the Yankees’ second win in three games raised their record to 34-33 and kept them seven games behind the AL East-leading Red Sox.

“When I found out I wished him a happy birthday,” said Pettitte, who halted a two-game skid, is 6-5, and tied Ron Guidry for fourth place on the all-time Yankees wins list with 170.

Matsui, who was 0-for-6 this season with the bases juiced, knew he had the advantage on Blanton even though Matsui had three hits in the 20 previous at-bats (.150).

“It’s the perfect situation: no outs and the bases loaded,” Matsui said of the mess Blanton had gotten himself in via an infield hit by Derek Jeter and walks to Bobby Abreu and Alex Rodriguez. “I was looking for a pitch up in the zone, something I could hit to the outfield. It was a change-up, up in the zone, and I put a good swing on it.”

A half-inning prior to Matsui’s last, Pettitte worked out of a sticky situation caused by Jason Giambi booting a potential double-play ball on Kurt Suzuki’s grounder with Daric Barton on first.

“It was already 1-0 and I knew their guy was throwing well and he had shut us down,” Pettitte said of Blanton, who dropped to 3-9. “I didn’t want to press and I got the opportunity for a strike out. I made good pitches and was able to get the strikeout.”

After fanning Bobby Crosby on a 0-2 pitch, Pettitte watched Jack Cust’s opposite-field drive to left push Johnny Damon to the wall for the final out. Starting with Jack Hannahan’s sacrifice bunt with nobody out in the fifth, Pettitte retired the next dozen batters before turning it over to Mariano Rivera in the ninth.

Working for the fifth day in six, Rivera walked Eric Chavez to start the ninth but retired the next three hitters in order for his 18th save in 18 chances.

“Hopefully this will get us rolling,” said Pettitte, who is 6-5 and put to sleep the vision of him giving up 10 runs and 10 hits in 62/3 innings in his last start. In a season-high eight innings, Pettitte gave up a run and five hits.

To date, nothing has gotten the Yankees going. But Chien-Ming Wang pitched very well Tuesday night and Pettitte was better last night than he had been all year.

So, maybe Matsui’s birthday gift to his mates will be the match that finally lights a spark.

george.king@nypost.com