Would you believe the Yankees and Mets are at each other's throats? We're not just talking the delicious Bronx-Queens rivalry that overheats during interleague play. Instead, the second half of Saturday's day-night, dual-site doubleheader -- which the Yankees swept by identical 4-2 scores -- was highlighted by Roger Clemens' beaning of Mike Piazza.

The Mets angrily accused Clemens of deliberately trying to hit their best player. And, after watching him leave the Stadium with a concussion -- Piazza was treated at the Hospital for Special Surgery in Manhattan -- Bobby Valentine spoke of revenge.

"I hope some day (Clemens) plays in the National League and we'll play against him," the Mets manager said. "I've seen him hit guys in the head before. I saw him hit Robby Alomar in the head after he tried to bunt on him.

"Aren't you paying attention? This guy is going to the Hall of Fame. He doesn't have that bad of control."

More? General manager Steve Phillips said, "there was no doubt" Clemens threw at Piazza, and called such tactics "horse (bleep)."

The epithets flew freely in the Mets clubhouse, partly due to the frustration of losing both games of this historic doubleheader, but also because they were inching closer to being swept altogether in this four-game series.

The Mets were privately hoping to catch and pass the Bombers all in one weekend -- not such a far-away fantasy, considering they had a better won-lost record than the world champs, had held their own in a dramatic series with the Braves a week before and were well aware of the Yankees' pitching crisis.

Clemens and Orlando Hernandez had been on the disabled list until last week, but even more troubling was David Cone's evaporation and the assembly line of rookies the Yankees had used in the starting rotation, all of whom had failed.

"A bunch of Bambis caught in the headlights," is how one Yankee veteran characterized the collective efforts of Jake Westbrook, Ben Ford and Ed Yarnall. The crisis became so severe that the Yankees actually turned their desperate gaze to Dwight Gooden, asking him to start the afternoon game at Shea on Saturday.

Doc's return to the Yankees was, in itself, enough to fuel this unique baseball marathon. After all, Gooden had been released by the Devil Rays last month, suffering the added insult of being told to retire. This, from the worst team in the American League.

But Gooden still asked for one more chance. It took 3½ weeks -- each day filled with self-doubt and fear and the possibility that "maybe it was time to start getting involved in my kids' lives and activities," Doc said -- but finally, the Yankees called.

Gooden learned a valuable lesson while working out at the club's minor league headquarters in Tampa. And that was this: Control -- and more importantly, control within the strike zone -- is the only way a 35-year-old pitcher can survive. Especially a former strikeout deity whose best fastball barely reaches 90 mph anymore.

That's why Doc allowed the Mets just two runs in five innings, because, as Yankees pitching coach Mel Stottlemyre put it, "he finally crossed the bridge" from thinking he could overpower hitters with his velocity.

Maybe it was his maturity, or perhaps it was his adrenaline overflow. Remember, Gooden was facing his former team, making his first appearance at Shea since 1994, not to mention his first start with the Yankees since 1997. The day was historic, all right, although no one could've foreseen the Clemens-Piazza fiasco later that evening.

Actually, the Rocket started dropping hints earlier in the week about Piazza, who'd crushed a gram slam against him June 9 at the Stadium, Game One of the first inter-borough series of the season.

The Rocket insisted that Piazza's blast would simply make him "more aggressive" in their next meeting. But the Mets were enraged that Clemens crossed the line between aggressive pitching and pure head-hunting. Clemens came up and in to Lenny Harris and Derek Bell in the first inning before finally nailing Piazza with a fastball that deflected off his wrist and into the side of his head.

It was an awful, terrifying result: Piazza lying on his back, totally motionless, laboring to remain conscious, it seemed. Not surprisingly, Clemens insisted he had no intention of hitting Piazza, and realizing the catcher had been injured, "left me shaken."

True or not, the Mets weren't buying it. Said Todd Zeile, "Roger was definitely trying to send a message. I've seen him pitch long enough to know his command isn't that off."

Asked how the Mets responded to Clemens' attack, Zeile said, "We all wanted to hit the ball off his forehead, and hit one out of the park."

That would explain why every Mets player stood on the top step of the dugout for the duration of the second inning, daring Clemens to come up and in again.

There were no other incidents Saturday. But there was enough leftover hostility to turn Sunday night's series finale into ... well, an entire city is waiting for an answer.