The simmering tension between Roger Clemens and Mike Piazza nearly got real ugly real fast.

In their first matchup since Clemens beaned Mike Piazza in July, Clemens came close to hitting Piazza again -- this time with the jagged barrel of a broken bat.

Clemens pitched the best World Series game of his career Sunday night, following up a one-hitter against Seattle in the ALCS with a two-hit, nine-strikeout shutout before leaving after eight innings in the Yankees' nervous 6-5 victory.

But it was Clemens' first-inning showdown with Piazza, who homered in the Mets' five-run ninth off reliever Jeff Nelson, that gave this game a raw edge.

With everyone watching in anticipation a nasty renewal of their confrontation, Clemens started the Mets' catcher with two called-strike fastballs over the inside corner of the plate Sunday night in Game 2 of the World Series, then threw a ball low and outside.

On the fourth pitch, Piazza fouled a grounder off a letter-high inside pitch and his bat shattered, with the largest chunk -- the barrel head -- going back to the mound.

Clemens picked up the splintered wood and threw it angrily in front of Piazza as he ran toward first, missing the Mets' star by about a metre.

Piazza, still holding the busted handle of the bat, turned and cursed at Clemens, then started toward the mound.

Clemens moved toward him, and plate umpire Charlie Reliford stepped between them.

Teammates from both dugouts and bullpens swarmed the infield.

There was a lot of pushing and shoving but no punches, and play resumed after about two minutes.

Reliford spoke with Clemens, and Piazza grounded to second on the next pitch.

"My fault, my fault," Clemens said, tapping his chest, as he spoke to Reliford for about a minute before returning to the Yankees' dugout.

"I came back into the dugout and I said I've got to get control of my emotions and calm down," Clemens said after the game. "I told Charlie, the umpire, I didn't know Mike was coming out.

"I guess it came close to him. That was my emotions."

When Clemens, a five-time Cy Young Award winner, hit Piazza in the head on July 8, the Mets said Clemens deliberately threw at him.

"I don't want to say he intentionally hit me in the head, but I think he intentionally threw at my head," a groggy Piazza said the following day.

"There's no place for that in baseball."

Clemens claimed the pitch in July got away from him.

"I have no respect or appreciation for his comments," said Piazza, who missed the all-star game because of the beaning.

"Roger Clemens is a great pitcher, but I don't have respect for him now at all."

Before Sunday's game, Yankees manager Joe Torre was asked again about the prospect of another confrontation between Clemens and Piazza.

Torre said he watched ESPN show, "Mike getting hit 36 times in 36 seconds. Kept standing him up. I guess that's what makes people watch."

"I'd like to believe they'd rather watch the World Series than to see if Roger Clemens is going to hit him again, or if Mike is going to throw the bat at him," Torre said.

The possibility of Piazza throwing the bat, or letting it go after a swing, might have been in Clemens' mind, too, when he saw the broken bat coming at him.

Perhaps in the instant he picked up the bat and threw it toward Piazza, Clemens didn't realize it was broken.

But no matter what was in Clemens' mind, the bad blood between them and the two clubs grew only worse with this incident.

In the fourth inning, Clemens may have sent another message when he hit leadoff batter Edgardo Alfonzo in the upper arm with the first pitch as Piazza stood in the on-deck circle.

Piazza then stepped in, smiled at Clemens, and took ball one.

Piazza worked the count full, with none of the pitches coming close to hitting him, before he fouled out to first baseman Tino Martinez.

After a throwing error by Clemens allowed Timo Perez to reach first on a bunt in the sixth, Piazza finally hit the ball hard against Clemens, lining an 0-2 pitch to left.

David Justice came in fast and made a terrific sliding catch, the back of his glove brushing the grass, as Piazza watched in frustration.

That catch preserved Clemens' one-hit, 4-0 shutout as the Mets failed to get a runner past first.

The only hit to that point by the Mets was a second-inning single by Todd Zeile.

Zeile got the Mets' second hit, another single, in the seventh.

Piazza is hardly the only batter to claim Clemens threw at him.

Seattle said Clemens deliberately threw at Alex Rodriguez in Game 4 of the AL championship series, and Mariners manager Lou Piniella retaliated by having Paul Abbott throw a pitch over the head of Yankees catcher Jorge Posada.

By Steve Wilstein