The United States was in trouble when Sam Querrey began his Davis Cup match against Thiago Alves on Sunday.A few booming serves later, the Americans were headed for the quarterfinals.Querrey beat Alves 4-6, 6-3, 6-4, 7-6 (3) to give the U.S. a dramatic 3-2 victory over Brazil, stepping up after teammate John Isner lost to Thomaz Bellucci to send the countries to the deciding fifth match."I was very happy with the way I battled through (the match)," Querrey said. "I fought through the tough points and got breaks in the second, third and fourth sets. I was just happy to get through it."Also advancing Sunday to the quarterfinals were: Canada (over Spain), Italy (over Croatia), Kazakhstan (over Austria) and the Czech Republic (over Switzerland). Clinching spots on Saturday were: France (over Israel), Serbia (over Belgium) and Argentina (over Germany).The U.S. will host Serbia in the next round in Boise, Idaho, from April 5-7. The other three matchups for the quarterfinals are France-Argentina, Canada-Italy and Czech Republic-Kazakhstan.Canada is in the Davis Cup quarterfinals for the first time. It defeated a five-time champion Spanish team that was missing Rafael Nadal, David Ferrer and Nicolas Almagro because of injuries and fatigue.No. 15-ranked Milos Raonic beat No. 82 Guillermo Garcia-Lopez 6-3, 6-4, 6-2 in the opening reverse singles in Vancouver, British Columbia, to give Canada an insurmountable 3-1 lead.It was the first time since 2000 that a U.S. team needed to win the fifth match to advance, and the 25-year-old Querrey started fast, breaking Alves in the second game. But Alves, ranked No. 141, responded with breaks of his own in the third and ninth games to take the opening set.Querrey responded with a consistent array of cross-court winners to control play the rest of the way.While Isner, the highest-ranked singles player in the tie at No. 16, bemoaned his play, Querrey expressed satisfaction with a straight-set win over Bellucci on Friday and the four-setter against Alves on Sunday.U.S. team captain Jim Courier had special praise for the 20th-ranked Querrey."Sam faced some adversity at the end and played a great tiebreaker to get past not closing it out on serve," Courier said. "Those are learning moments for a player, things you can draw on later on in your career. Today is a good day for Sam and our team in a lot of ways."Querrey was especially effective with his serve. He finished with 26 aces, compared to one for Alves, often clocking 120 mph or faster. When Alves was able to return a serve, it often was with little pace, enabling Querrey to eventually hit winners."I fight for all the match, all the match," the 30-year-old Alves said. "My ranking is 145, something like this. I play two guys under 20 in the world. I think I play great tennis here."Isner got off to a fast start in the first match of the day, then went on to a 2-6, 6-4, 6-7 (7), 6-4, 6-3 loss to the 25th-ranked Bellucci.The left-handed Brazilian overcame Isner's powerful serve with a strong display of groundstrokes that kept the 6-foot-9 American off balance. He played his best tennis in the second part of the match, breaking Isner in the 10th game of the fourth set and then the eighth game of the fifth set.A dejected Isner said he needed to improve both his mental frame and his play on the court."This hurts a lot. I could have won this match," he said. "I just couldn't quite win the big points. It's almost like I wanted it too badly. Confidence-wise, I'm not even close to where I want to be."You can't sugarcoat it with me. My five-set record is atrocious, it's simple as that. It falls on me."The United States now has nearly three months to get ready for Serbia, which features the world's No. 1 ranked player in Novak Djokovic. Courier said the U.S. team welcomes the challenge of taking on the talented Serbs."We wanted to face Serbia. They're one of the great Davis Cup nations right now," Courier said. "If you want to lift this trophy, you need to beat the best teams and that certainly is one of them. We look forward to the challenge."