Djokovic reaches quarterfinals at Key Biscayne, with straight-sets victory over Robredo

Novak Djokovic, of Serbia, returns to Tommy Robredo, of Spain, at the Sony Open Tennis tournament, Tuesday, March 25, 2014, in Key Biscayne, Fla. (AP Photo/Lynne Sladky) (The Associated Press)

Tommy Robredo, of Spain, returns to Novak Djokovic at the Sony Open Tennis tournament, Tuesday, March 25, 2014, in Key Biscayne, Fla. (AP Photo/Lynne Sladky) (The Associated Press)

Three-time champion Novak Djokovic has reached the quarterfinals of the Sony Open, topping Tommy Robredo 6-3, 7-5.

The second-seeded Djokovic converted his only two break points of the match, then finished it off with a crosscourt forehand winner Tuesday.

Djokovic essentially gave back a point in the second set. A groundstroke from Robredo clipped the baseline and Djokovic couldn't handle it, but the ball was erroneously called out. After a review showed the ball was in, the point was ordered to be replayed.

Djokovic shouted "It's OK, it's OK" as the fans at Key Biscayne applauded his sportsmanship.

The start of play was delayed nearly an hour by rain. Andy Murray, Serena Williams, Roger Federer and Rafael Nadal were all scheduled for matches later in the day.