Roger Clemens had long since departed for the safety and sanity of the visitor's clubhouse by the time Pedro Martinez collected the last of his 12 strikeouts. He was not around for the change-up that fooled Tino Martinez, just as he hadn't been around for the fastball that had Joe Girardi leaning the wrong way or the change-up that baffled Bernie Williams.

Had Clemens stayed around to watch, he would have known what the citizens of Red Sox Nation have known for a while: Pedro Martinez is the best pitcher on Earth.

On a gorgeous New England afternoon that featured two of baseball's best hurlers on center stage, Martinez made the stage his own with a dazzling seven-inning, 12-strikeout performance that led the Boston Red Sox to a 13-1 victory over the New York Yankees in front of 33,190 at Fenway Park.

Martinez had plenty of support from an offense that pounded Clemens for five runs in two-plus innings and collected 21 hits in all, including six doubles and home runs from John Valentin, Brian Daubach and Nomar Garciaparra. The Red Sox jumped Clemens for two quick runs in the first inning and had run it to 6-0 after three innings and 8-0 after five.

They were in such command that Red Sox Manager Jimy Williams had the luxury of removing Martinez after 105 pitches, hoping he'll have the chance to bring him back for a decisive Game 7.

After opening this best-of-seven series with a pair of one-run losses at Yankee Stadium, the Red Sox narrowed the series to 2-1 with Games 4 and 5 also at Fenway Park. The loss ended the Yankees' record-tying 12-game postseason winning streak.

Martinez dominated the Yankees on a day when he said his back ached on every pitch and his velocity suffered as a result. He has the best change-up in the game, but he normally uses that change-up to complement a 96-mph fastball. Today, the change-up was his primary pitch, and because his control and sense of the game are so superb, the bottom line didn't change as he allowed two singles and extended his postseason shutout streak to 17 innings.

"He is an artist out there," Yankees Manager Joe Torre said. "He has a baseball instead of a paintbrush."

Martinez departed Game 1 of a first-round series against Cleveland with a strained muscle in his back. He was able to return in time to pitch six hitless innings in Game 5, and this evening was back on the mound again. If the results were the same, Martinez wasn't.

His blazing fastball was nowhere to be found, and after the game Martinez said he surprised even himself.

"I had nothing," he said. "I didn't have a fastball. I didn't feel like I had a good breaking ball or good change-up. I just managed to spot the ball and mix them in there. I am hurting, and I am not lying."

On Sept. 12, he struck out 17 in a game at Yankee Stadium. He was on his way to 17 more before being removed with the Red Sox leading, 9-0. But this one was totally different.

"I pretty much mixed my pitches and hit the spots," Martinez said. "When they were looking for a change-up, I threw a little cutter. When they were looking for a breaking ball, I was throwing a little sinker away. The hardest I threw was probably 89 miles per hour."

Clemens was a different story. Red Sox fans got a full measure of revenge against their former favorite son by alternately booing him, taunting him and derisively chanting his name. Clemens said he barely noticed the crowd, even when he was warming up in the bullpen only a few feet from them, but he must have sensed that he was in an extremely hostile environment.

"I was locked in pretty good," he said. "You expect that in opposing stadiums anyway."

Clemens had known what to expect after spending the first 13 seasons of his career here and winning three Cy Young Awards and tying Cy Young himself with 192 career victories. He had known feelings ran deep and wondered aloud on Friday how he would deal with his runaway emotions and whether "I can hold up my end of this deal."

He didn't come close. He was out of the game almost before he was in it, allowing five runs and six hits in two-plus innings. Red Sox leadoff man Jose Offerman hit his second pitch off the wall in left for a triple, and Valentin followed by lofting a two-run home run onto the screen above the Green Monster.

The Red Sox scored two more in the second, and when former teammate Mike Stanley led off the third with a single, Clemens was gone. He took perhaps the longest and most painful walk of his magnificent 16-year career this afternoon when he made the long trip from the mound to the visitor's dugout as the Fenway faithful unloaded their anger on him.

Afterward, he was the perfect gentleman, praising Martinez for his performance and saying he picked a bad day to have a bad day.

"I knew what I was up against, and obviously I'd love to make a better showing than that," Clemens said. "Everything happens for a reason. I will continue to work as hard as ever. It's one game and our guys will come back out."

With the game essentially decided by the third inning, Torre saved his bullpen by leaving mop-up man Hideki Irabu in to surrender eight runs in 4 2/3 innings. After the game, Torre thanked Irabu for absorbing the beating that gives the Yankees a rested bullpen for Sunday's Game 4.

Asked about momentum, Williams, the Sox manager, shrugged and smiled.

"The score tomorrow when we start is nothing to nothing," he said. "So we start all over. It's a great game, isn't it?"