CINCINNATI — Carlos Beltran hit the last of New York’s three homers last night, a seventh-inning grand slam off Eric Milton that powered the Mets to an 8–3 victory over the Cincinnati Reds.

Xavier Nady and Jose Valentin also hit solo homers that helped right-hander Mike Pelfrey improve to 2–0 after two major league starts. The 22-year-old rookie gave up seven singles and a pair of runs in six innings.

A first-round draft pick last year, Pelfrey was called up from Double-A on July 7 to help a shorthanded rotation. He’s expected to get at least one more start.

Beltran’s grand slam off Milton was the sixth of his career and his second in two games. He and Cliff Floyd connected Sunday during a club-record 11-run sixth inning that set up a 13–7 win against the Cubs at Wrigley Field.

Beltran added a run-scoring double in the ninth off left-hander Bill Bray, acquired in an eight-player trade with Washington last week. The loss was Cincinnati’s first since the All-Star break, coming off a four-game sweep of Colorado.

The Mets have won five of their last six games, improving the NL’s best record to 56–37. New York has led the NL East by double-digits since June 22.

Pelfrey, who was born at Wright Patterson Air Force Base in nearby Dayton, is the third Mets starter to make his big-league debut this season. He won on July 7, allowing three runs in five innings of a 17–3 win over Florida.

The 6-foot-7 pitcher was under a lot more pressure the second time around, but came through again. He also got Milton to fly out with the bases loaded in the second, and fanned Adam Dunn on a 96-mph fastball with two aboard in the fifth.

Beltran is 2-for-5 with the bases loaded this season.