Kirk Gibson hit a bases-loaded triple in a six-run fifth inning as the Detroit Tigers completed their first four-game sweep in Boston's Fenway Park since 1973 last night, beating the Red Sox, 8-2.

Right-hander Dan Petry (6-3) allowed only five hits, three in the fourth inning, for his first victory in Boston since joining the Tigers in 1979. Detroit has won five in a row and 12 of 15.

"They just plain beat us tonight with that one big inning, but we could have won two of the games as easy as we lost time," Boston Manager Ralph Houk said. "There's no question, though, that Detroit is hot. They've got everything going their way right now."

Detroit took a 2-1 lead against starter Dennis Eckersley (4-3). Alan Trammell beat out an infield hit and, with two out, Lance Parrish hit his fourth homer.

With two out in the fourth, Boston tied the score on a walk, a double by Wade Boggs and single by Cal Yastrzemski. Dave Stapleton followed with another hit before Petry ended the inning by getting Jeff Newman to ground into a force play.

The Tigers loaded the bases on a walk, a single by Bill Fahey and another walk with one out in the fifth. Alan Trammell singled for the tie-breaking run, and Gibson followed with his triple to the base of the wall in left-center.