“The longer the match went on, I realized I had to change up my game. I played differently than I was hoping to be able to. He got more comfortable as the match went on. Obviously, once I was down a set I knew it was going to be difficult. I’m happy to be out there and able to compete, but it’s obviously a small issue. That doesn’t work against guys like Rafa, obviously.”

Victoria Azarenka and Sam Stosur both withdrew from their quarterfinal matches today.

“I should have won easier,” said the outspoken Latvian, who was also a qualifier in his previous event at Delray Beach where he ran all the way to the title. “I played better than him the first set. I played better than him the whole match, I think. It’s just that the first match just mentally I destroyed myself, and that’s what happened.”

“There are some few adjustments that I need to make and get a little bit sharper on the court,” said Djokovic, who will next face American Ryan Harrison. “But it’s expected in the first match you’re still not a 100 percent on the court.”

On a packed opening day Australian Open schedule, Novak Djokovic begins his title defense.

Roger Federer ranks No. 1 among all athletes in Australia.

At the WTA Championships Thursday it was Serena Williams beating down Victoria Azarenka for an 11th time in 12 meetings.

Women’s Notes: (1) Stosur after a bye could open against Cornet, and (3) Wozniacki after a bye against the Slam winner Schiavone…Pulling from the event were Marina Erakovic, Sara Errani, Kaia Kanepi, and Aleksandra Wozniak…Returning champs in the field are Cibulkova (2011) and Schiavone (2009).

Here’s are my early favorites for the US Open.

Andy Roddick’s downward trajectory, the return of Kim Clijsters, and reigning Wimbledon champ Petra Kvitova in action are the things to watch this week, the final warm-up week before Wimbledon.