Best known as the only major leaguer to hit two grand slams in a single inning, Tatis delivered the first three extra-base hit performance of his career, the Elias Sports Bureau said.
The Mets' winning streak is their longest since a seven-game string in August 2006. Tatis contributed in a big way Sunday, too, with a two-run homer in the 12th inning that beat Philadelphia.
David Wright doubled twice, and scored the go-ahead run in a four-run seventh inning. It was his last bid to earn the final spot on the NL All-Star team - Internet balloting closed shortly after the game, and the public-address announcer at Shea Stadium frequently urged fans to text in their votes for Wright.
The Giants ended their scoreless streak at 21 innings, but still lost their fourth in a row.
Scott Schoeneweis (1-2) won in relief of John Maine.
Tatis hit his fourth homer, a two-run drive into the left-field bleachers off Sergio Romo (0-1) in the seventh. The Mets added two more in the inning on a throwing error by third baseman Jose Castillo and a single by Jose Reyes.
Tatis, who had been out of the majors since 2006 when the Mets promoted him in mid-May, raised his batting average over .300. The crowd chanted his name when he came up again in the eighth inning, a nice reward for a 33-year-old utilityman whose best days seemed far behind him until recently.
Shut out by the Mets the previous two nights, the Giants scored in the fourth when John Bowker doubled and later raced home on Maine's wild pitch.
A righty, Maine exited his last start because of a cramp in his left forearm. Against the Giants, he matched season highs by striking out eight and walking five - Maine faced 21 batters and went to a full count on 10 of them.
Ahead 3-1 with two outs in the fifth, Maine lost a chance at a win because of Randy Winn. After Winn lined a tying double for just the Giants' second hit, Mets manager Jerry Manuel pulled Maine.
Tatis' second double of the game drove in two runs and put the Mets ahead 3-0 in the third. Carlos Beltran hit an RBI single, then ran right through third base coach Luis Aguayo's stop and easily scored when the throw home was cut off.
Beltran had a chance to break open the game the next inning after Barry Zito walked the bases loaded with two outs, but grounded out.
The end of that threat also meant the end of a lunch break for a half-dozen construction workers watching from new Citi Field. A row of yellow hard hats had been perched on an upper level, beyond the center-field scoreboard.
Notes: Zito got a no-decision and avoided becoming the first pitcher to lose 13 times before the All-Star break since Detroit's Jeremy Bonderman and Mike Maroth in 2003. Denny McLain holds the major league record for losses by the All-Star break with 15 in 1971. ... Maine drew a walk from Zito in the fourth. The next inning, Zito drew a walk from Maine and scored his first run of the year.
