BOSTON — Alfonso Soriano continued to flex his biceps in pitchers’ faces and Mark Reynolds couldn’t have made a better first impression.
However, for those who believe the Yankees can come all the way back and eke into October, Andy Pettitte was the story Friday night.
Soriano homered and drove in four runs and Reynolds, signed Thursday off the street, homered in his first Yankees plate appearance.
Yet, it was Pettitte who was the headliner in a 10-3 Yankees victory that was witnessed by a Fenway Park crowd of 38,143 more interested in booing Alex Rodriguez than supporting the suddenly slumping Red Sox.
The AL East leaders have lost seven of 11 and are 7 ½ games ahead of the fourth-place Yankees, who haven’t been this close to the lead since July 29. The Yankees have won six of eight.
Not having won since July 11, a span of five starts in which he was 0-3, Pettitte (8-9) went 6 ²/₃ innings, allowed three unearned runs — thanks to two errors by Eduardo Nunez — and six hits.
With a revamped lineup sparked by Soriano’s torrid stretch of 18 RBIs over four games (which ties the all-time record), stretched by the addition of Rodriguez and augmented with the signing of Reynolds (who will play first base against lefties), the onus to get the Yankees in the playoff picture is on the starting rotation.
“I believe we have a chance to get back into it,’’ manager Joe Girardi said before the game.
Considering his experience and track record before this year’s disappointment, an effective 41-year-old Pettitte is a must.
Reynolds, who was let go by the Indians on Aug. 14, is the 14th Yankee since 1961 to homer in his first plate appearance. He finished with two hits and three RBIs.
Nunez made two errors (one fielding, one throwing) and they led to unearned runs in the fourth and sixth innings.
The Red Sox pushed Pettitte from of the game in the seventh when Mike Napoli’s two-out single scored Jonny Gomes and cut the Yankees’ lead to 7-3.
Shawn Kelley replaced Pettitte with runners on first and second and two outs, and caught pinch-hitter Mike Carp looking for the final out. Carp reacted by slamming his helmet to the ground and pointing aggressively in umpire Bill Welke’s face before being ejected.
David Robertson worked the eighth and was extracted from a jam when David Ortiz’s one-out liner with runners on first and second was nabbed by Rodriguez, whose toss to Robinson Cano at second doubled off Shane Victorino for the final out.
Heavily booed, Rodriguez lined into a double play in the first, singled to right in the third, walked in the fifth, lined to center in the seventh and singled sharply to center in the ninth.
The Yankees scored three runs in the ninth to stretch the lead.
Red Sox starter Felix Doubront lasted four innings, gave up seven runs (six earned) and eight hits.
It was easily his worst start against the Yankees. The lefty had produced quality starts in all six previous outings against the Yankees and was 3-1 with a 2.17 ERA in those games. Since 1980, the only other pitcher with quality starts in his first six games against the Yankees was Jarrod Washburn, from 1999 to 2006.
Pettitte allowed one run and three hits in the first five innings. The run scored in the fourth inning on Gomes’ two-out single. However, Gomes was picked off for the final out with the Red Sox trailing by six runs.
When Pettitte took the mound for the home fifth, he lugged a 7-1 lead with him thanks to home runs by Reynolds and Soriano.
With the Yankees leading, 1-0, thanks to Soriano’s two-out RBI single in the first inning, Reynolds’ first at-bat as a Yankee produced a two-run homer over the Green Monster. Vernon Wells, who walked leading off the inning, scored ahead of Reynolds’ 16th homer of the season.
Nunez singled to start the third and Cano’s grounder in the hole at short wasn’t handled cleanly by Stephen Drew. With two runners on and none out, Soriano crushed a homer to left-center.
Soriano began the game with 14 RBIs and four homers in his previous four games.
Cano upped the lead to 7-0 in the fourth with a single that scored Nunez from third. Nunez tripled to center field with one out.