(Reuters) - The New York Yankees blasted the Texas Rangers and their recently acquired pitcher Ryan Dempster 8-2 on Monday to take over top spot in the American League.

In the series opener between the best two teams in the AL, the Yankees issued a strong statement of intent in front of their home fans by scoring eight unanswered runs to make it a miserable day for Dempster after Texas had started brightly.

In just his third start for the Rangers (67-47) after the team acquired him to bolster their ailing pitching staff, Dempster was charged with all eight runs in just six innings.

A struggling Dempster also surrendered eight runs in his debut for Texas.

"You've got to execute pitches," Dempster told reporters. "It's that simple. I have to do a better job of it."

Nick Swisher led the power surge with a grand slam in the third inning that put the Yankees (68-47) 4-2 ahead and they never looked back.

Swisher finished with five RBIs and Eric Chavez also homered for New York as they drew first blood in the four-game series.

Starter David Phelps, deputizing for the injured C.C. Sabathia in the rotation, tossed five innings for the win while new reliever Derek Lowe handled the final four scoreless innings to secure the save.

Lowe was making his debut with the Yankees after they acquired him this week to help with the absence of Sabathia.

"I don't know how you can ask two guys to do any more than that," Yankees manager Joe Girardi said.

"To hold a team like Texas down to two runs and give yourself a chance to win a ball game, that's really stepping up."

(Reporting by Jahmal Corner in Los Angeles; Editing by John O'Brien)