The biggest story — literally — in tennis last weekend was 6-9 American John Isner, whose upset of Roger Federer in the first round of the Davis Cup in Switzerland led to a surprising 5-0 U.S. sweep of the Swiss. It was the first American Davis Cup sweep since the first round of the 2004 Cup.

Isner called the 4-6, 6-3, 7-6 (7-4), 6-2 victory “the biggest win of my career,” although the most historic remains his marathon win over Nicolas Mahut in the first round of Wimbledon in 2010, the longest match in tennis history. It stretched 11 hours 5 minutes over three days before Isner finally won it 70-68 in the fifth set.

Since that day at Wimbledon, Isner has risen to No. 14 in the world and proven he is more than just a giant with a booming serve. The Davis Cup success over Federer gives him a boost of confidence heading into the Delray Beach International Tennis Championships on Feb. 27-March 4, a 32-man tournament that also includes 17th-ranked Andy Roddick.

“I can obviously take a lot of good things away from this weekend,” Isner said on Sunday in Switzerland. “I definitely played top-notch tennis. Tricky conditions, in Europe, February, on clay. It’s not something I’m used to doing, coming over here this early.

“I do realize now, no matter the surface, no matter the opponent, a lot of times, the ball, the point, the match is going to be in my control no matter who I’m playing, no matter if it’s Roger Federer or somebody who isn’t even ranked. I really have to make a conscious effort of doing everything in the future that I did this week.”

Isner impressed U.S. Davis Cup captain Jim Courier, the former world No. 1.

“I learned that John can beat anyone at any time, because no one has a chance if he plays the way he plays and serves the way he serves, unless they play incredible defensive tennis,” Courier said. “I don’t know I have ever seen anyone finish a match against Roger Federer the way he did. That was pretty amazing.”

The United States will play France in the quarterfinals April 6-8.

Watching from home was Roddick, who is back on the court this week after retiring in the second round of the Australian Open with a torn hamstring tendon.

“It was exciting,” Roddick told USA Today of the Davis Cup win. “I was proud. It was like I was a fan again. It was awesome.”

He said Isner and Mardy Fish, ranked No. 8, deserve the Davis Cup spots over him.

“It’s not even worth me talking about,” said Roddick, 29. “It’s their team. The last thing I’m going to do is come here and create headlines by saying I want back in. … They deserved it. They both won. It’s their team right now. I mean, if they get hurt, then it’s a conversation. Jim’s been great. He’s made it known to me that the door is open, but first of all, I’m the third-ranked guy.”

• Isner and Roddick will be joined in Delray’s 32-man field by No.23 Marin Cilic, No. 24 Viktor Troicki, No. 33 Alex Bogomolov, No. 37 Jurgen Melzer, No. 40 Donald Young and No.57 James Blake. Roddick opens play Feb. 28. Tickets are available at 561-330-6000 or at yellowtennisball.com.

• A month later, on March 24, top-ranked Novak Djokovic plays his opening match at the Sony Ericsson Open at the Crandon Park Tennis Center in Key Biscayne. Djokovic, Rafael Nadal, Federer, Andy Murray, Caroline Wozniacki, Kim Clijsters and Serena Williams are in the field.

For tournament tickets, call 305-442-3367 or go to sonyericssonopen.com.