Keith Urban, Nicole KidmanGoing back to the event where they first met in 2005, Keith Urban and wife Nicole Kidman surprised the crowd by appearing on stage together at this weekend's 'G'Day USA Ball' in Los Angeles and performing a song paying tribute to fellow Aussie, Simon Baker.

While Keith sang a humorously revised version of the Men at Work classic, 'Down Under,' Nicole danced playfully around him, occasionally singing along. "His name is Simon Baker," they sang. "Surfer dude. Home renovator. He was bound to be a Hollywood player ... He's CBS's big money maker. 'The Mentalist' a ratings maker." (Watch video of the performance, after the jump.)

While accepting his award for Australian excellence in film and television, Simon exclaimed his appreciation. "Wow! That song is something. That was a bit of a treat."

Actress Toni Collette and golfer Greg Norman were also among the folks being honored at the annual gala.