FOXBORO -- The crowd was roaring, but Deltha O'Neal didn't hear a thing.

"I didn't hear anything but my heartbeat," he said.

Hearts were pounding in Gillette Stadium with the Kansas City Chiefs five yards away from the game-tying touchdown, facing a fourth down with 40 seconds left in the game.

Pats fans had had their hearts in their throats midway through the first quarter, when superstar quarterback Tom Brady went down with what appeared to be a serious knee injury.

They breathed a bit easier when little-used Matt Cassel came off the bench and led the Pats to a seemingly safe, 17-10 advantage, courtesy of a 37-yard field goal by Stephen Gostkowski with 2:26 remaining.

But the situation took a dramatic turn for the worse when KC's second-string QB -- former Patriots backup Damon Huard -- threw a 68-yard completion to Devard Darling, who got past Brandon Meriweather, then eluded free safety James Sanders, on second-and-16 from the Chiefs' 27-yard line.

Three plays -- two incompletions and a run by Larry Johnson -- failed to gain a yard, which meant the game was on the line when Dwayne Bowe, the Chiefs' best receiver, lined up against O'Neal on the right side of the KC formation.

"They have two guys who are top dogs," said O'Neal, a nine-year veteran who only signed with New England on Monday after being cut by Cincinnati. "That's Tony Gonzalez, the tight end, and number 82 [Bowe].

"When you see 82 line up on your side, there's a 99.9 percent chance he's gonna get the ball."

Instead of being anxious in such situations, O'Neal says a sense of calm -- and concentration -- comes over him.

"It's like it's silence, all around me," he said. "I don't hear the crowd. I don't hear anything but my heartbeat."

Playing man coverage on a receiver like Bowe could give a lesser man than O'Neal a heart attack.

"You've got to be tough and physical with him off the line," he said. "If the ball comes his way, you've got to do whatever you can to get it out of his hands."

What O'Neal did was hit Bowe's hands just as the ball arrived. Or perhaps even a split-second before the ball arrived.

"I slapped at his hands right before the ball got to him," O'Neal said. "He was looking for a flag."

But he didn't get it, and the Patriots got a hard-fought -- though if Brady's out for an extended period, Phyrric -- victory.