Young American Harrison defeats No. 15 Ljubicic

Ryan Harrison wants to be the next American tennis star. The composed and confident 18-year-old from New Braunfels, Texas, won the biggest match of his career Wednesday, ousting No. 15 seed Ivan Ljubicic, 6-3, 6-7 (4), 6-3, 6-4.

This is the fourth match that Harrison has won at the National Tennis Center this week, having won three times in the qualifier to get into the main draw for the first time.

Harrison turned pro at age 15 and won a tour-level match a month short of his 16th birthday. He didn't win another tour match until at Indian Wells this spring, then he lost to Ljubicic, the eventual champion.

"To win on this stage here and to take out a top 20 player in the world is the biggest win of my career," Harrison said. "I've always believed in myself."

He is mentored by Andy Roddick and coached by his father Pat, a good college player. Harrison radiates confidence, though without bravado. Still, when asked if he was up to the challenge of being America's next star, he replied:

"Absolutely, I want to be that guy."

Ivanovic breezes

Ana Ivanovic had a rare easy match, looking more like a top 10 player than the 40th-ranked player that she is. Ivanovic, once the No. 1 player in the world after winning the French Open in 2008, beat the 21st seed Jie Zheng, 6-3, 6-0, in the first match in Ashe Stadium.

Ivanovic, who suffered a power outage when her confidence sagged, looked like a power player Wednesday. She dismissed Zheng's ineffectual first serve and swatted away her second serve. She advanced past the second round of a Grand Slam event for the first time this season.

"I remember a couple of years ago when I was here and I was saying even though I'm No. 1, I don't feel I'm playing as No. 1," Ivanovic said. "But [now] I feel like I'm playing like a top 10 player, and I have confidence that I can beat these players. That's huge for me."

USTA, Usher join forces

The USTA announced that its charitable arm, USTA Serves, is partnering with hip-hop star Usher's New Look Foundation. The foundation fosters creative and athletic pursuits of youngsters across the country in hopes they will become global and community leaders.