BOSTON -- On most nights, if the Yankees score five runs and Randy Johnson allows just five hits over seven innings, the Bronx Bombers will leave the ballpark with another notch in the win column.

But this is Yankees-Red Sox, where the rule is to expect the unexpected.

The Big Unit allowed three home runs in a game for the first time in 21 months, helping Boston to an 8-5 victory at Fenway Park. Johnson allowed five runs on five hits, striking out nine, while Tom Gordon allowed three runs in the eighth inning to account for the margin of victory.

"I'll take five runs any time, and with Randy, you may not need that many," said manager Joe Torre. "He didn't give up many hits, but unfortunately, the hits were home runs."

The pitching wasn't the ugliest thing in the game for New York, however, as Gary Sheffield was involved in an altercation with a fan in the right-field stands during the decisive eighth inning.

With the Sox already leading by one, Jason Varitek lined a two-run triple down the right-field line, making it a three-run game. As Sheffield went to field the ball at the foot of the wall, he said he was hit in the mouth by a fan who may have been trying to reach for the ball, prompting him to take an abbreviated swing at the spectator before throwing the ball back to the infield.

Sheffield didn't appear to make contact with the fan, Fenway security intervened quickly and no further swings were taken, though the game was stopped for a few minutes as tempers settled down.

"It could have been worse if I didn't hold my composure," Sheffield said. "I almost snapped, but I thought about the consequences."

"He was angry," Torre said. "It's one thing going into the stands, but it's another thing defending yourself when somebody gets on the field."

The incident overshadowed another bizarre game between the two bitter rivals. Boston didn't have much success overall against Johnson, but when the Red Sox put the bat on the ball, they made their hits count.

Kevin Millar singled in the second, setting up Jay Payton's two-run blast to center field. The next inning, Johnson issued a one-out walk to Johnny Damon, then served up a mistake to Edgar Renteria, who drilled it over the Green Monster to give Boston a 4-1 lead.

"He had good stuff," Torre said. "But when he made pitches not where he wanted them, they cost him dearly."

New York answered in the fourth, batting around against Bronson Arroyo. With the bases loaded and two outs, Arroyo thought he had Sheffield struck out on a 3-2 pitch, but home plate umpire Greg Gibson called a ball, forcing a run home. Hideki Matsui followed with a two-run double to tie the game, then Alex Rodriguez singled in the go-ahead run to put New York ahead, 5-4.

Jason Varitek didn't wait long to tie it up, crushing a one-out solo shot high over the Green Monster. That last time Johnson allowed three homers in a game was Aug. 15, 2003, when three Braves took him deep at Turner Field.

"They hit two good pitches," Johnson said. "Varitek hit a good fastball, and Jay Payton. The one mistake that I made cost me two runs, the hanging slider to Renteria. I thought I pitched pretty well, but you look at the linescore, I gave up five runs. You're not going to win a lot of ballgames giving up five runs."

Johnson allowed five runs on five hits and two walks, striking out nine in seven innings, leaving with the score knotted up at 5. Last season, Johnson allowed five runs in two of his first four starts, then went on to do so just twice over the remainder of the season.

"You give up five hits, you're not thinking about giving up five runs," Johnson said. "I know we're going to score runs. Even if we get 10 runs a game, I don't like giving up runs. All you do is put your team in a hole, and the last two games, I've put our team in a hole."

"Right now, his stuff isn't overpowering like it's going to be," Torre said. "He settled in and made some pitches. Unfortunately, the bad pitches he made were home runs, not singles or doubles."

Tom Gordon relieved Johnson, a welcome sight for the Sox. Damon led off the eighth with a single, then Renteria ripped a double off the Monster, scoring Damon all the way from first to give Boston a one-run lead. Varitek's two-run triple, which incited the Sheffield incident, gave the Sox some insurance runs. Keith Foulke, who tossed a scoreless eighth, earned the win after escaping a bases-loaded jam in the ninth.

"On the day that I pitch, I expect us to win," Johnson said. "Now I have to wait four more days."