Derek Jeter's three-run homer capped a six-run second inning and the New York Yankees extended Boston's stunning collapse by beating up the Red Sox 9-1 on Saturday afternoon at Yankee Stadium.

Rookie catcher Jesus Montero had three hits with a homer and four RBIs and Freddy Garcia (12-8) tossed six scoreless innings to reduce New York's magic number to one for clinching home-field advantage throughout the American League playoffs.

The loss - Boston's 17th in 22 games this month and first at Yankee Stadium this season - cut its wild-card lead to 1 1/2 games over the Tampa Bay Rays, who defeated Toronto on Saturday night. Boston's lead is 2 1/2 over the Los Angeles Angels.

Meanwhile, the Red Sox received another putrid performance from a starting pitcher. Ace Jon Lester (15-9) was ravaged for eight runs in 2 2/3 innings in losing his third straight start to fall to 8-3 lifetime against New York.

In the last 19 games, Boston starters have a collective 7.37 ERA. The Red Sox are 4-15 in that stretch.

Russell Martin had a two-run single in the second on a fly ball that was dropped by Red Sox left fielder Carl Crawford. Jeter hit the next pitch into the seats in right-center for only his second homer since July 25.

With Friday’s series opener rained out, the teams will play a day-night doubleheader Sunday.