Philadelphia ? Trot Nixon got back at the Philadelphia Phillies in a big way.

Nixon capped a six-run ninth inning with a grand slam as the Boston Red Sox rallied to beat the Phillies, 13-9, Monday.

Nixon went 3-for-4 with a career-high six RBIs for the Red Sox, who began a crucial nine-game road trip with the win and moved within one game of idle Seattle for the AL wild card.

“This is a really big win for us,” Nixon said. “It gives us momentum and that’s something we hope to carry through the rest of the road trip.”

Nixon wanted revenge for a 6-5 loss to the Phillies in the teams’ first meeting on June 21 in a similar game that had both teams seesawing into the lead. He also wanted to get payback for being hit in the right wrist by a pitch in the eighth inning.

“We wanted to get them back for earlier in the year,” Nixon said. “But these kind of games might take a few years off my life. As long as we win them, it’s OK, though.”

The Phillies took a 9-7 lead in the eighth, but the Red Sox rallied against closer Jose Mesa (5-7).

Philadelphia manager Larry Bowa, who exploded in a team meeting after being swept by Montreal Thursday, appeared frustrated afterward but kept his cool after the game.

“We battled back, but just couldn’t stop them,” he said. “No question, it was a peaks- and-valleys day.”