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Will Middlebrooks hit a grand slam in the midst of an eight-run sixth inning, as Boston ripped Detroit thanks to eight home runs, 20-4, in the rubber match of a three-game series.

David Ortiz went deep twice and knocked in four runs for the Red Sox, who took the set and have won nine of their last 11 thanks to exploding for a season- high in runs scored.

Stephen Drew, Daniel Nava and Ryan Lavarnway each clubbed a two-run shot, with Jacoby Ellsbury and Mike Napoli adding solo homers.

"It was a rare and outstanding offensive night tonight," Red Sox manager John Farrell said.

Ryan Dempster (8-9) gave up four runs on six hits with seven strikeouts and two walks over six innings for the victory.

Prince Fielder hit a two-run homer, with Torii Hunter and Jose Iglesias driving in a run apiece for the Tigers, who have dropped three of four. Iglesias eventually left the game with shin splints.

Rick Porcello (11-8) was torched for seven hits and nine runs -- eight earned -- over five-plus frames. Detroit's bullpen was responsible for 12 hits and 11 earned runs for the remainder of the contest.

Ahead by one, Boston blew the game open in the sixth.

Nava worked a leadoff walk and Napoli doubled off the Green Monster before Drew was issued a free pass to load the bases. Pinch-hitter Mike Carp showed his patience to force in a run, then Al Alburquerque came in for Porcello and served up the slam to Middlebrooks which put the hosts in front by a 10-4 margin.

Two batters later, Shane Victorino was plunked, then Ortiz collected his 2,000th career hit when he doubled him home with two down in the frame and Nava then reached the bullpen for a two-run homer and 13-4 lead.

The onslaught continued in the seventh, as Lavarnway added a two-run homer just over the Monster which was upheld by review, Quintin Berry singled home another run to make it 16-4 and Ortiz slammed one into the bullpen for a 14- run bulge.

Napoli went deep in the eighth and Berry later singled home Lavarnway to reach the 20-run plateau.

"It was pretty ugly. ... They were hitting it around like ping pong balls," Tigers manager Jim Leyland said.

It looked good for the AL East leaders from the outset, as Nava singled with one down in the home second and Drew launched a two-out, two-run shot over the Pesky Pole for a 2-0 lead.

Detroit struck with three in the third on Hunter's RBI groundout and a two-run blast from Fielder, but Ellsbury tied the game in the home half on a homer that just cleared the low wall to the left of the right-field pole.

The Tigers loaded the bases in the fourth on an infield hit, double and walk, then went ahead as an Iglesias grounder scored a run.

Ortiz began the home half with a long homer to right, then the Sox took the lead in the fifth as Victorino singled with one out, stole second and moved to third on Tigers catcher Alex Avila's wild throw, then came home on a Dustin Pedroia liner.

Game Notes

Boston opens up a crucial four-game series in the Bronx on Thursday ... The Red Sox previous best for runs in one game this season came in a 17-5 demolition of Texas on June 4 ... The last time the BoSox eclipsed the 20-run mark came on June 27, 2003 in a 25-8 romp over the Marlins ... The Sox also tied a franchise best with eight homers on Wednesday, matching a mark originally set on July 4, 1977 in a 9-6 win against the Blue Jays at Fenway Park, when Fred Lynn and George Scott clubbed two apiece, with Jim Rice, Butch Hobson, Bernie Carbo and Carl Yastrzemski going deep once each ... Nava has reached base in a major-league best 39 consecutive games ... Prior to the contest, the Chicago Cubs claimed reliever Daniel Bard off waivers from Boston.