First was the impassioned halftime speech he delivered to a defense that had been picked apart on the Giants' home field by a resurgent Jacksonville team. And second was the play that ultimately sealed the Giants' stirring second-half comeback - a potential season-saver - in their 24-20 win.
Now I'm the first to admit that halftime speeches often are the most overrated part of a football game, and rarely have that "Win one for the Gipper" effect that people like to believe. NFL halftimes usually are so brief that players barely have time to sit down and get a drink, and even less time to go over strategic issues with coaches, and hardly can fit in the kind of dramatic soliloquy worthy of anything more than a bunch of hot air.
But this one was different, in part because of what was said, but more because of who said it and what he did about it with the game on the line.
Tuck came under early-season criticism for his somewhat subdued style of leadership, an approach that runs counter to the more in-your-face approach of many captains, especially former defensive players Antonio Pierce and Michael Strahan.
Tuck said he hadn't planned on delivering any halftime sermon on this day. But once he heard defensive end Osi Umenyiora light into his team for its lackluster play in a first half in which the Giants gave up 236 yards and left the field to a chorus of boos trailing 17-6, he knew it was time.
"If I paid as much as they did for their seats and we played as badly as we played, I'd probably boo, too," Tuck said.
At some point during Umenyiora's excoriation of his teammates, Tuck decided to add his own thoughts at a decibel level not usually reached by the mild-mannered, think-before-you-speak defensive end. This time, Tuck let them have it.
"A lot of times you'll have guys screaming, and it's just in one ear and out the other," defensive tackle Barry Cofield said. "But I was near tears hearing some of the things that Tuck had to say. He proved why he's the captain."
Tuck spoke of the need to play with passion and purpose, of refusing to be embarrassed "in our house." He put it to his teammates as bluntly as possible that the defense's play was unacceptable. And he included himself in that mix.
"I just challenged each of them," Tuck said. "I told them that I was playing like crap, I told them that we were playing like crap, and that in the second half, we needed to pick it up. I just tried to create a spark."
And that is precisely what he did. After the Giants were mauled in the first half, giving up an unseemly 145 rushing yards and allowing David Garrard to scramble at will, they were dominant in the second half, limiting the Jaguars to a field goal.
Even so, after Eli Manning put the Giants ahead with his second touchdown pass of the day - a 32-yarder to Kevin Boss off a blitz with 3:15 to play - Jacksonville still had a chance. And it was Tuck who made a play to ensure the win.
After Garrard completed three passes to help the Jaguars move from their 27 to the Giants' 29, 1:51 remained and the game seemed in doubt. Garrard took the shotgun snap and faded back to pass, but with Antrel Rolle bearing down on a safety blitz from the defensive right, Tuck knifed through the line. Tuck went low, Rolle went high and Garrard went down for an 11-yard sack.
Garrard was sacked twice more, by Jason Pierre-Paul and then by Terrell Thomas, and fumbled each time. Rolle recovered the second one, and the Giants wound up with the ball at the Jaguars' 39.
Tuck's defense did its job, reviving the Giants' hopes after it looked as if their season would continue its downward spiral. But now they're 7-4 and tied for first with the Eagles again.
"It was a day that Justin definitely solidified himself as a captain," Cofield said. "You can get the title, but when the bullets are flying and when things come to a boiling point, that's when leadership rises."
So no more doubts about Tuck's leadership. After yesterday, it's unquestioned.