NEW YORK — Yankee Stadium has a history of drama on the Fourth of July.

There was Lou Gehrig's farewell speech in 1939, and Dave Righetti's no-hitter against Boston in 1983. It's George Steinbrenner's birthday, so it's always an important date to circle on New York's calendar.

Kevin Youkilis made the final Fourth at the ballpark truly memorable, sparking a come-from-behind 6-4 victory for the Red Sox on Friday with one of the strangest triples you'll ever see.

Mike Lowell drove in four runs, including a tiebreaking, three-run homer in the fifth against Darrell Rasner (4-7), who lost for the seventh time in eight starts. But Youkilis created the lasting memory, hitting a drive that left New York's Johnny Damon with a sprained and bruised left shoulder, a momentum turner that sent the punchless Yankees to their fifth loss in six games.

"This could be a big trouble spot for us," Damon said.

With New York leading 3-1 in the third, Youkilis hit a two-out scorcher with two on. Damon raced back, jumped and gloved it but as he crashed into the left-field fence, the ball popped out of the webbing of his glove. It bounced up off the top of the wall.

And bounced. And bounced.

The ball came to rest on top of the fence, which was shaking from Damon's impact. And there the sphere sat, like the golf ball teetering over the cup in "Caddyshack." The sellout crowd of 55,130 at Yankee Stadium wondered: Would it fall behind for a home run, roll back onto the field or just sit there?

"It was bizarre," Lowell said. "I've been playing awhile. I've never seen anything like that before."

Finally, the ball dropped back in and landed near Damon, who was sprawled on the warning track. A fan behind the fence frantically pointed to the ball. Youkilis cruised into third base as Boston tied it at 3.

Damon checked his glove to determine whether he made the catch. Then he looked around for the ball.

"I had no clue," he said. "When I didn't see it at first, I thought it might have been a home run."

Damon threw the ball back to the infield, threw his glove down and left the game. An MRI revealed a sprained acromioclavicular joint, and Damon said he would be out at least a few days. If the pain doesn't subside, he could wind up on the disabled list for the first time in a 14-season major league career.

Damon apologized to Rasner for not making the catch. He wasn't sure whether the shoulder popped out, and couldn't say whether he momentarily blacked out.

"I can't really move it too well," he said. "It's in the socket now. Structurally, everything is fine. And now I just have to deal with the pain and the inflammation."

What would have been the call if the ball had remained on the top of the fence?

"That ball is live, so if that ball had stayed on top of the fence, it would be have been interesting," umpire crew chief Wally Bell said. "We're going to have to find out exactly what the ruling would be on that."

Even Mike Port, Major League Baseball's vice president of umpiring, wasn't positive.

"The guess is that if it had stayed there, it would have been a home run because it had broken the front plane, but we'll discuss it with supervisors in the next few days," he said. "The great thing about this game is that after 100 or more years, you still see things that may not have happened before."

The Yankees have dropped nine of 14 following a seven-game winning streak.