By Liza Horan

There was no calm before the storm on U.S. Open eve.

Prince took over several courts at Central Park for its EXO3bition, honoree Andre Agassi and others hit the Easthampton for a charity exhibition, the Bryans brothers took the stage at the Mercury Lounge, and two launch parties drew manufacturers and players.

At noon, fans met and played with Gael Monfils, Bob and Mike Bryan, Sam Querrey and others at Prince's "Get Out and Play" event in Central Park.

Upon goading by emcee Wayne Bryan, Stan Smith (top right) partnered with musician Michael Johns, a former college scholarship competitor who made finalist in American Idol Season 7, to see who was better at keeping volleys in play. Johns lost that one, but he aced a spur-of-the-moment a cappella rendition of "Stand by Me." Even better, he got Smith to sing along.

One lucky fan, Josh Berman (left) , got to play against No. 13 Monfils. The nine-year-old is ranked 17th in the 10s for USTA Eastern. Even though Monfils was impaired by having to holds hands with someone while he played, the Frenchman managed. Still, Berman scored autographs on photo slicks, a ball and his hat.

An online auction to benefit the City Parks Foundation generated $8,000. The top bid: $5,000 for a half-hour private lesson with the Bryan twins. [Related Story: Bryan brothers, always accessible to fans, become NYC media darlings]

"Every year before the U.S. Open we try to bring the pros into the park so the public can see them up close and have a chance to interact, hit a few balls, have some fun and this year Prince stepped up, with TENNIS.com, and brought out their players," said Mike Silverman of the City Parks Foundation, which handles all sports programming in the parks. Click here for "Tennis participation is growing in NYC parks."

As evening fell manufacturers helped celebrate the recent opening of NYC Racquet Sports near Times Square, and KB Sports Management officially launched with a rooftop party. KB Sports represents Jesse Whitten, Lester Cook and Prakash Amritraj, among others.

The head of a major tennis wholesale business said he had been at the tennis center early in the day, sitting in Arthur Ashe Stadium and watching Rafael Nadal practice with Fernando Verdasco.

"He looked tired, had his head down and was slouching a bit, you know. Then Roger Federer walked out with Stanislas Wawrinka because they were next on court to practice. Both Davis Cup teams were there: Spain and Switzerland. As soon as Roger walked out, Rafa started killing it. He was making every shot. And when it was Roger's turn to practice, Rafa stayed out there, sitting in the stands, watching."