Querrey beat Jan Hajek 6-3, 7-5 on Thursday to put the U.S. 1-0 up against the Czech Republic in the Red Group and remain unbeaten in his three singles this week.

The second singles and a doubles will be Friday. The Americans are bidding to win a fifth title, but first since 1993.

"So far so good," said Querrey. "I thought today was the best I played out of the three matches. So I'm pretty excited."

Hajek claimed the first break, when Querrey ended a long rally with a forehand error, to go 3-1 up but the American player responded by winning the next five games in a row to take the opening set.

Both players saved a break point late in the second set before Querrey broke at 6-5, converting his third match point.

"I've been working this week to try and hit my forehand a little bigger. I felt I did that today," said Querrey. "I felt pretty much anytime I got a forehand, I was able to take control of the point."

Querrey said his win takes the pressure off the U.S. ahead of Friday's matches.

"A little bit, yes. I think John (Isner) can go out there and play a little more freely, which is a good thing," Querrey said. "When we have the lead, you can swing away a little bit more than if we were 1-0 down.

"Then, the Bryan brothers, we expect them to win every match. Hopefully, they are going to do that again."

The winner of the match between France and Argentina, which stands at 1-1, will qualify from the Blue Group.

Jeremy Chardy put France ahead by beating Juan Monaco 6-3, 6-4 but Eduardo Schwank tied it with a 3-6, 6-3, 6-2 victory over Paul-Henri Mathieu. The deciding doubles is Friday.