Klahn family photo Bradley Klahn, an aggressive, athletic lefty and graduate of Poway High, answered the call to serve as Roger Feder's practice partner after participating in the Junior Wimbledon competition. It would be Klahn's job, in the hours leading up to the men's final to play the part of Rafael Nadal, also a left-hander.

After several calls between Federer's agent and a coach for the United States Tennis Association, Federer found his man. It was Bradley Klahn, an aggressive, athletic lefty.

Klahn, 17, a graduate of Poway High this spring, was available after participating in the Junior Wimbledon competition. It would be Klahn's job, in the hours leading up to the match, to play the part of Nadal, also a left-hander.

“It was pretty special to warm up possibly the greatest player of all time,” Klahn said.

Little did Klahn know that his practice session on July 6 would be a prelude to what is being called one of the greatest Grand Slam finals of all time. Federer, owner of 12 Grand Slam championships, had his string of five straight Wimbledon titles snapped by Nadal, who triumphed in a five-set match that lasted 4 hours, 48 minutes.

For Klahn, trading shots with Federer on an outer court at Wimbledon provided an exclamation point to his first visit to London's All England Club. The youngster found himself in awe of the venue's atmosphere and history.

“At Wimbledon, it's hard to explain,” Klahn said. “I've been growing up watching it so much. It was hard to believe that I was actually there and playing.”

In singles, Klahn won two matches before falling in straight sets to third-seeded Cesar Ramirez of Mexico. Klahn teamed with American Ryan Harrison in doubles, where the second-seeded tandem lost in the quarterfinals.

Klahn has competed in three junior Grand Slam events this year, establishing himself as one of the world's top young players. He is ranked 17th in the International Tennis Federation junior world standings. In the United States, Klahn is ranked third in the Boys-18 Division.

In the Junior Australian Open, Klahn lost in the third round of singles, but not before downing the tournament's 14th seed. He did not fare as well in the Junior French Open. On the red clay of Roland Garros, Klahn lost in straight sets in the opening round of singles and doubles.

Despite his early exit at the French Open, Klahn relished the experience. He and his mother, Nancy Klahn, spent the extra days in Paris, touring the city and visiting sites such as the Louvre and the Eiffel Tower.

“Just being at those tournaments, the Grand Slams, there's such an electric atmosphere,” Klahn said. “There's so much energy – the crowd, the sights, the history – especially at the French and Wimbledon. It's pretty cool to know that you've played there.”

Later this summer, Klahn will complete his Grand Slam tour at the Junior U.S. Open in New York.

“To play in all the Grand Slams before he goes to college was exciting for him and the rest of the family,” Nancy Klahn said.

Next season, Klahn will take a break from the international scene to play tennis at Stanford. His ranking and mental toughness made Klahn a blue-chip recruit at Poway, where he won the San Diego Section singles championship as a junior and helped the Titans win two section team titles.

Klahn said he hopes to refine his game at Stanford, gain strength and help the Cardinal win an NCAA championship.

“If his success in the past is any indication of the future, I think he has a great chance of being a professional tennis player,” said Lee Merry, Klahn's personal coach.

Merry, who has coached Klahn since he started to play competitively at age 11, spent two years on the pro tour in the 1970s.

Klahn said when the time is right, he will give the pro tour a shot. Someday, perhaps Klahn will have a chance to compete against Federer instead of warming him up.

 Jake Fisher is a Union-Tribune intern: jake.fisher@uniontrib.com