A new center fielder and the Jason Giambi of old helped the Yankees extend their winning streak to five.

Giambi homered for the third straight game and 20-year-old Melky Cabrera singled in his major league debut as Mike Mussina and the Yankees beat the Cleveland Indians 7-2 last night.

Alex Rodriguez homered for the second straight game, tying for the AL lead with 22 on the season, and Derek Jeter also connected for New York.

Aaron Boone returned to Yankee Stadium for the first time since 2003, when his 11th-inning homer off Boston’s Tim Wakefield won Game 7 of the AL championship series. Boone, who received an ovation from fans, went 2-for-4 with two singles.

Giambi added an RBI single and raised his batting average to .274, the highest it’s been since he went 1-for-2 in the season opener, and he boosted his homer total to nine. He has four home runs, two doubles, and a single in his last 10 at-bats, and has homered in three consecutive games for the first time since July 11-13, 2003.

Cabrera became the first player to make his big-league debut as the Yankees’ starting center fielder since Bernie Williams on July 7,1991, according to the Elias Sports Bureau. He went 1-for-4, showed decent range, and displayed a strong arm. Manager Joe Torre said before the game that Cabrera would likely start all four games of the series, a move that will even further decrease the playing time of Tony Womack.

Mussina (9-5) allowed two runs and six hits in seven innings, lowering his ERA to 3.97. Tom Gordon relieved in the eighth but left after three batters with an unspecified injury.

Cleveland’s Kevin Millwood (3-7) dropped to 0-3 in his career against the Yankees, giving up six runs and seven hits in six innings. He retired his first two batters with 0-2 counts and went 0-2 on Gary Sheffield, who singled to left. Rodriguez followed with a drive just over the right-field wall.

Johnny Peralta’s 10th homer cut the lead in half in the second, but Giambi homered leading off the bottom half. Rob Marchese, a 41-year-old businessman from Queens sitting in a folding chair in the first row in the right-field stands, fumbled away both Rodriguez’s and Giambi’s homers.

Grady Sizemore pulled Cleveland to 3-2 with a RBI grounder in the fifth, but New York broke open the game with a three-run sixth. Hideki Matsui had an RBI single, Millwood threw a run-scoring wild pitch when he slipped on the mound and Giambi hit an RBI single.

Jeter homered off Fernando Cabrera leading off the seventh.

To make room for Cabrera, the Yankees put right-hander Carl Pavano (sore shoulder) on the 15-day disabled list retroactive to June 28.