Blake overcame his history of fifth-set woes, fighting off two match points to beat Paul-Henri Mathieu 7-6 (5), 6-7 (3), 6-3, 3-6, 7-5 on Friday to give the U.S. a 2-0 lead in the best-of-five competition.
Roddick ripped 30 aces on the fast hard court in a 6-4, 7-6 (3), 7-6 (5) win over Michael Llodra in the opener. But it was Blake's comeback that stirred the partisan crowd and moved the U.S. within a victory of the semifinals.
"It's a little more dramatic than I wanted it to be, but you're going to have to win some of these, too," Blake said. "The more dramatic ones are going to be the ones that probably stick in my memory. This one, I won't forget for a long time."
"It's disappointing because 1-1 we still had a bit of a chance," French captain Guy Forget said. "At 0-2 it's getting very, very difficult -- almost impossible."
In the other Davis Cup quarterfinals, Russia was tied 1-1 with the Czech Republic in Moscow; Rafael Nadal led Spain to a 2-0 lead over host Germany, and Argentina and Sweden were tied 1-1 in Buenos Aires.
Blake, who lost the first nine five-set matches of his career, now has won three of four. He appeared finished when Mathieu was serving at 5-4, 40-15 in the fifth set. But Blake battled back to eventually break Mathieu after two deuces.
Blake then broke Mathieu's serve for the fourth time two games later to close out the nearly 4-hour match.
"I always thought my five-set record, it was just one of those things that was going to be broken at some point," said Blake, who insisted the poor record was due to bad luck, not poor fitness.
After Mathieu's final forehand hit the net, Blake had enough energy to jump in the air and yell. He was then quickly embraced by his teammates, including Roddick, who took a much easier path against Llodra for his win.
Llodra had 26 aces of his own in a powerful, if unexpected, matchup after Australian Open finalist Jo-Wilfried Tsonga withdrew earlier this week because of a right knee injury.
With Richard Gasquet slowed by a blister on his right hand, Forget went with Llodra. The strong left-hander constantly attacked the net and had his serve broken only once, but couldn't overcome Roddick's blistering serve.
"I thought he played well and I had to play really good stuff today to get through," Roddick said.
Roddick fended off his first three break points at 5-5 in the third set, closing out the game with consecutive aces. Fittingly, he converted his second match point in the third-set tiebreaker with a service winner.
Roddick then belted a ball into the stands as teammates and his fiancee, model Brooklyn Decker, cheered him on.
"I would like to return more, but it's difficult," Llodra said. "It was a good match, but not enough to beat him."
The Americans' first home Davis Cup competition since ending their 12-year title drought last year started with an elaborate celebration. Amid fireworks and a light show, each team member received a championship ring and raised the title banner before the first match.
"It was great to get it and see it, but to be honest I was trying to almost blank out during all of it, just because I knew I had to play a match," Roddick said. "Seeing all those highlights and seeing the guys with the rings, I don't know if I wanted to get too emotional or caught up. And Lord knows I don't need to get even more nervous before Davis Cup matches."
After it took four people to push the gigantic Davis Cup trophy off the court, you could hear the whirring sound from the ball as Llodra defensively tried to return Roddick's monster serves.
Then Blake came alive late in the second match, frustrating Mathieu, who was so close to a big win on an uncomfortable surface.
"I don't think it slipped away. The guy played great after he saved the two match points," Mathieu said. "He made some very good shots, even in the last game. He played great."