The New England Patriots stood just over a minute from unique perfection. The aristocrats of American football were a mere 75 Super Bowl seconds from immortality, poised to complete the longest undefeated season by any team in the history of US professional sport.

The New York Giants trailed 14-10 and faced a third down and five yards to go from inside their own half. Eli Manning, their young quarterback, was smothered by Patriots defenders and looked certain to be sacked, leaving the Giants just one long, presumably hopeless fourth down from a bitter defeat.

But Manning somehow escaped the defenders and threw a long pass that seemed to be sailing high over the head of wide receiver David Tyree. The unsung and underused Tyree, who had only four catches in the entire regular season for the Giants, leaped, his arms knotted with a Patriots defender, and managed to bring the ball down as he fell to earth, between his hand and his helmet, in what will surely rank as one of the most extraordinary catches in Super Bowl history

It took the Giants to the Patriots 24-yard line and kept New York’s slim hopes of victory alive. Four plays later, Manning threw a short pass to wide receiver Plaxico Burress for the touchdown that, with just 35 seconds left to play, would give the Giants one of the biggest upsets in Super Bowl history and ended the dream of perfection for the Patriots.

“I think we shocked the world tonight,” said jubilant Giants veteran defensive player Michael Strahan “Well, in a lot of ways we shocked ourselves. You know what? Nobody expected us to win. I’ll be honest, even when my parents were telling me:

“You’re going to win”, I don’t know if I believed them either.”

The touchdown all but ended a low scoring defensive struggle that turned into one of the most thrilling finishes in the history of America’s biggest sporting event. The Giants 17-14 last gasp victory marked only the second time in the history of the Super Bowl that a team had won after trailing in the final minute.

The lead changed hands three times in the fourth quarter and the Patriots seemed to have wrapped up victory when Tom Brady, their star quarterback, with three Super Bowl victories already behind him, led his team on an 80-yard drive capped by a touchdown pass to wide receiver Randy Moss, with less than three minutes to play.

But the Giants had one last improbable run in them to crown an improbable season. While the Patriots were breaking records, going undefeated in 16 games in the regular season, and two in the playoffs, scoring more points and more touchdowns than any team in history, the Giants were struggling with mediocrity. They lost their first two games, giving up 80 points in the process. In a city that had been starved of any sporting success in the last decade, and had watched as its hated rivals up the coast in Boston had won everything, anger at head coach Tom Coughlin and at Manning reached boiling point.

But Coughlin’s team mounted a comeback propelled by a remarkable run of wins on the road, that stretched to a National Football League record-breaking 11 games, right the way to the Super Bowl. The run included a win at Wembley stadium in October in a driving rain and a swamp against the Miami Dolphins.

Manning’s cool under pressure in leading the Giants on that final game-winning drive gave him the game’s Most Valuable Player title and an unprecedented back-to-back triumph for the Manning family. His brother Peyton, won the honour a year ago with the Indianapolis Colts.

But the real key to New York’s victory was a stout defence. They held the explosive Patriots to their lowest points total of the season, sacking Brady five times, also a season high for the New England quarterback.

Apart from the Giants, the other winners on Sunday were the remaining members of the 1972 Miami Dolphins team. With New England’s defeat, Miami remains the only team to have competed an entire season, including the Super Bowl, undefeated. They played only 14 regular season games, against the Patriots 16, but managed to win the one that counted most, the final one.

“The Patriots had a great season,“ said Don Shula the coach of the 1972 Dolphins after the game. “But it shows how difficult it is to go undefeated. Our players and our fans feel that much more proud of our accomplishment.”

The Patriots’ misery at the Super Bowl was compounded by a widening controversy over alleged cheating by the team’s coaches.

The Boston Herald reported on Saturday that a Patriots official had filmed their opponents’ final practice before New England won its first Super Bowl six years ago. The Patriots upset the heavily favoured St Louis Rams in that game to win 20-17. Teams can gain a significant advantage by knowing the defensive plans of their opponents and coaches go to great lengths to maintain secrecy in their communications.

Patriots officials vigorously denied the allegations on Saturday but the team’s reputation had already been sullied by a proven case of cheating earlier this season.

In September the National Football League punished the Patriots after it was discovered that a New England official had secretly filmed defensive play signals by the New York Jets’ coaches during the opening game of the season. The NFL called the spying “a calculated and deliberate attempt to avoid long-standing rules designed to encourage fair play”, fined Bill Belichick, the New England head coach, $500,000 and ordered the team to forfeit a first round pick in the college draft.

That controversy also deepened at the weekend when the minority leader of the Senate Judiciary Committee said he might call hearings to investigate the way the NFL had handled the case. Sen Arlen Specter said he planned to call on the NFL to explain why it had destroyed the videotapes after its investigation. He said he was considering calling on Roger Goodell, the NFL commissioner, as well as Patriots’ players and coaches, to testify before congress.