If the surprising world champion New York Mets of 1969 were known as the "Amazins," the wild-card Mets of 1999 certainly must be the "Little Amazins." Reserve catcher Todd Pratt, substituting for ailing star Mike Piazza, hit a series-winning home run over the center field fence with one out in the bottom of the 10th inning this afternoon for a 4-3 victory that eliminated Arizona and lifted the ecstatic Mets into the National League Championship Series starting Tuesday in Atlanta. The Braves also advanced this afternoon, eliminating Houston with a 7-5 victory.

A crowd of 56,177 at Shea Stadium went wild, standing and cheering for almost a half-hour after Pratt began jumping up and down just before reaching second base when he realized that his hit off Diamondbacks closer Matt Mantei had cleared both the fence and leaping center fielder Steve Finley. Finley said the ball ticked his glove as it vanished over the fence.

"I felt like I should have caught it," Finley said. "It hit the end of my glove. But I've caught a lot of those before."

By that mere inch or so, the Mets had dispatched Arizona, three games to one, in the NL's opening playoff series. It was one of the most dramatic moments in the history of a franchise that has had its share of them, but not many recently.

The Mets players were too overcome with emotion even to leave the field, gathering in a big circle along the first base line, congratulating themselves on their unlikely ascent almost from extinction late in the regular season. Pratt, the unlikely hero, had gone 0 for 6 in his two games as replacement for Piazza, who had a reaction to a cortisone shot in his sore left thumb Thursday, causing the thumb to swell. Piazza, working on a $91 million contract, had to make way for a substitute so humble he refused to take credit for the victory.

"I knew it had a chance," Pratt said of the ball that he watched grow smaller and smaller as it headed toward the fence just to the right of the 410-foot sign in the deepest portion of center field. "I saw Steve set himself for his jump. We've seen it a million times where Steve pulls back a home run. I lost sight of the ball. I thought he had it. Then he put his hand down. We won the game."

"It's over. It's over," fans cried out. Police quickly surrounded the field to prevent anyone from the roaring crowd to make it onto the field.

The Mets' victory ended a remarkable week begun with a playoff victory over Cincinnati to gain the wild-card berth. The breathtaking final run was made possible by an "amazin'" eighth inning in which the upstarts scored a game-tying unearned run, resulting from a dropped fly ball by makeshift right fielder Tony Womack. Roger Cedeno drove in the tying run with a sacrifice fly one play after Womack muffed a deep drive by John Olerud for a two-base error, putting runners on second and third.

Womack had just been switched from shortstop to start the inning amid a flurry of moves by Arizona Manager Buck Showalter in a futile effort to stave off the Mets.

The bottom of the eighth also was marked by a violent argument between Mets third-base coach Cookie Rojas and left field foul line umpire Charlie Williams. Rojas shoved the umpire with both hands to the chest, resulting in his ejection.

Mets Manager Bobby Valentine and several others had to restrain Rojas, who claimed that a line drive by Pratt that might have produced the winning run was fair. But replays upheld the umpire, showing that the ball hit the dirt in front of the left field foul pole just wide of the chalk in foul territory. By that mere fraction, the Diamondbacks were able eventually to survive the inning and prolong the tense, suspenseful struggle in which the Mets stranded 10 runners.

Arizona took a 3-2 lead in the top of the eighth when Jay Bell greeted Armando Benitez, relieving starter Al Leiter, with a two-run double. At that moment the vision of a Game 5 back in Arizona with Randy Johnson pitching for the Diamondbacks hushed the crowd. Benny Agbayani had put the Mets ahead 2-1 in the sixth with a double that scored Rickey Henderson, who was on third base. Henderson starred in the series with six hits in 15 at-bats, six stolen bases, five runs scored and three walks. And after Valentine replaced him with rookie Melvin Mora for defensive purposes at the start of the eighth inning, Mora threw out Bell trying to score from second on a Matt Williams single with a game-saving bullet to Pratt, who leaped to celebrate after making the tag.

Edgardo Alfonzo hit his fourth home run of the week to give the Mets a 1-0 lead in the fourth inning off Arizona starter Brian Anderson. Greg Colbrunn tied the game with a home run with one out in the top of the fifth, the first of only three hits allowed by an effective Leiter over 7 2/3 innings.

A shaken Showalter said that at first he thought Finley had caught the ball, but then realized the Diamondbacks' season was over.

"Unless you've been through . . . the words to describe this . . . my vocabulary is not that good. You win 101 games, whatever, and then you're a spectator."

He had just spoken briefly with his players, the first second-year team ever to make the playoffs after winning the NL West easily. "I told them the pain will pass," he said. But, from the look of him, it would take time.

"I can tell you my immediate emotion is one of pride--is that an emotion?" asked Valentine. "Heck, we were looking over our shoulder at Randy Johnson. We were able to come back, with a little help," meaning Womack's error.

Like his players, Valentine jumped joyously on the field, experiencing something he hadn't "since I was in the minor leagues." Valentine had managed 1,704 major league games before reaching postseason play.

"We have something special going," he said. "It's a special group of guys. It's going to take a good effort to stop us. The next team is going to play against some ghosts because they said we were dead. I don't know if that team has ever played against ghosts."

Rojas claimed that Williams called him an "SOB" and made contact first with him. "Cookie is the heartbeat of our team, most of the time," Valentine said. "Cookie was called something and he blew a gasket." Pratt was the opposite of Rojas--totally calm, trying to deflect attention.

"There are 24 or 25 guys in our room who think he's a hero," said 39-year-old John Franco, a Met since 1990, who pitched the 10th inning and got the victory. Reflecting on all the Mets' recent good fortune, Franco added: "You know, the dropped fly ball, the reserve catcher hitting the game-winning home run. Maybe there is something going on here."