Listed as questionable prior to the game with rib and toe injuries, Tennessee quarterback Steve McNair passed for more than 300 yards and three touchdowns. One of the scores came on a nine-yard pass to tight end Frank Wycheck with nine seconds left to bring the Titans within two.
McNair then tied the game by running for the two-point conversion.
"I didn't know (if I would play) until game time, but I threw the ball with a lot of velocity in the pregame," said McNair, who completed 30 of 43 passes and finished seven yards shy of tying a career-high in yards. "The offensive line did a tremendous job of protecting me."
"This ranks with the best of them," Titans Coach Jeff Fisher said of McNair's performance. "He was very iffy. He could not practice. Let me tell you, if Steve could practice, he's going to practice. He's the first to tell you he needs the practice. We just kind of held faith in the medical staff getting him ready to play."
The win was the sixth in seven games for the Titans (7-5), who stayed one gamebehind division leading Indianapolis (7-4) in the AFC South. Tennessee will host the Colts next week.
The loss was the second in a row for the Giants (6-6) and severely damaged their playoff hopes.
"This was one of the most disappointing losses I have ever been involved in," said Giants Coach Jim Fassel.
After the Giants (6-6) scored 17 points on their first three second-half possessions to take a 26-14 lead, McNair engineered touchdown drives of 72 yards and 81 yards in the final 7:34. In between, Matt Bryant kicked a 19-yard field goal.
"He (McNair) is a tough guy," Wycheck said. "Time in and time out he rises to the occasion. I didn't think he would play this weekend. He did what he had to do to get ready. He plays with a lot of pain."
Giants coach Jim Fassel decided to go for a two-point conversion after Tiki Barber scored on a one-yard run 45 seconds into the fourth quarter in hopes of giving New York a 14-point lead. But the two-point attempt failed, leaving New York with a 26-14 lead.
"It made sense to me," said Giants quarterback Kerry Collins, who was 22 of 36 for 283 yards and two touchdowns. "If we get two, we go up 14 or two touchdowns."
That lost point, however, cost the Giants a chance to virtually seal the game when Bryant kicked his third field goal of the game with just 2:21 left.
"The chart says 12-point lead, go for two," Fassel said. "There are a lot of factors to consider. You do it late in the game, not early in the game because you never know how the numbers are going to tumble.
"They had to drive the length of the field in two minutes and get two points. The chances of that happening are not good."
Eddie George scored on a one-yard run to cap a 14-play, 72-yard drive, pulling the Titans within 26-21 with 7:34 left. McNair completed a 21-yard pass to rookie running back John Simon on third and nine before George bulled into the end zone on a third and goal.
The Giants held the ball for more than five minutes, but the drive stalled at the Tennessee two and they settled for Bryant's field goal, making the score 29-21.
"We get down to the one, we have to punch that thing in," Collins said. "We didn't get it in, we got three and allowed them to be in a position to tie the game."
"I think the biggest play of the game was the defense not allowing them to score there to go up by more points," said Titans receiver Derrick Mason, who finished with 12 catches for 116 yards and a touchdown.
McNair then directed a 12-play, 81-yard drive, running for 11 yards to the New York 29 and hitting Drew Bennett with a 20-yard pass to the nine before firing the touchdown pass to Wycheck.
Needing a two-point conversion to tie the game, McNair called his own number on a quarterback draw and raced untouched into the end zone.
The Giants won the overtime coin flip and took the ball instead of the wind, which was blowing at 31 miles per hour. After Delvin Joyce returned the kickoff 38 yards to the 40, Kerry Collins hit Ron Dixon with a 14-yard pass to the Tennessee 46.
But Amani Toomer was called for offensive pass interference on the next play for a 10-yard penalty and the Giants were forced to punt.
After a 34-yard punt by Matt Allen, the Titans took over at their own 20. McNair dissected the Giants again, completing three passes for 47 yards to set up Nedney's winning field goal.
"If they put me in there for a 38-yard field goal I better make that thing," Nedney said. "I knew that as long as I aimed it down the middle the wind wasn't going to do a thing with it."
McNair's heroic performance came a week after he was intercepted four times in a 13-12 loss at Baltimore.
"Steve is a warrior. He is our captain and leader," Mason said. "If Steve is doing well this team is doing well. We are all going to have some bad days but it's how well you bounce back from a bad day. Regardless of what anyone else might say, to me Steve is the best quarterback in the NFL."
The teams combined for 821 yards. Along with throwing for 334 yards, McNair ran for 38 more and the Titans rushed for 142 yards.
George surpassed Earl Campbell's franchise record for rushing yards and finished with 64 yards on 20 carries.