No. 1 seed Novak Djokovic overcame the loss of the second set in his match against Spanish qualifier Daneil Gimero-Travel to qualify for the last 16 of the Mutua Madrid Open 6-2, 2-6, 6-3.

The Serb also had to overcome some problems with the court and was visibly annoyed after slipping twice on the controversial blue clay surface, which is being used in Madrid, before powering his way to victory in the final set.

Djokovic looked like a man with a mission in the first set and barely allowed Gimeno Traver breathing space on the center court.

His first serve was effective and when he failed with his first service attempt, his second serve also gave his rival problems in returning.

Djokovic also hit half of the number of unforced errors that Gimeno-Traver made alone. There was only going to be one outcome -- after a brief wobble in the third game, the top seed broke his rival's serve in the fourth game and again in the eighth to take the set 6-2 in just 33 minutes.

Everything changed in the second set as Gimeno-Traver produced a brave fightback. He broke Djorkovic's serve in the third game, after the Serb was unable to control a forehand drive, held his own serve to love and then broke Djokovic again to go 4-1 up, to the delight of the partisan Spanish crowd.

The World No. 1 had a chance to pressure his opponent in the final game of the set, but saw how Gimeno-Traver successfully defended two break points before winning the game and taking the set 6-2 to level the match.

The start to the final set was delayed for a couple of minutes after Djokovic slipped on the court, which had received too much water after the second set. The Serb had previously commented that he was not very happy with the decision to play the tournament on the blue beaten clay surface, but kept focussed to serve out to love.

He slipped again in the second game and complained to the umpire that the court was too wet. Maybe his anger served to inspire him as Djokovic then played some of his best tennis of the match and was able to win what had turned into a potential upset.

Djokovic had followed local favorite Feliciano Lopez onto the center court, but No. 13 seed Lopez was unable to give the Madrid fans much to cheer about as he lost in three sets 3-6, 7-6, 6-4 to Jurgen Melzer, with the beaten clay doing little to favor the big- serving Spaniard.

No. six seed Tomas Berdych had a straightforward 6-4, 6-3 win over Kevin Anderson.

In the women's tournament, Maria Sharapova defeated Klara Zakopalova 6-4, 6-3 in a straightforward win in which the No. two seed's serve was a decisive factor.

"We really try to take every small opportunity in these tight situations and it is really important to hold your serve. In that way you are able to put a bit more pressure on the server when a set is 5-all or 4-all," said Sharapova, who admitted that the controversial blue clay court in Madrid was slightly slippery, but said she didn't see any problem with the color and that it had looked good when she had seen games on TV.

Top seed Victoria Azarenka was forced to work hard for a 6-3, 7- 6 victory against the Czech qualifier Andrea Hlavackova.

In other men's competition, former finalist David Nalbandian lost 6-4, 6-4 to Canadian Milos Raonic. Radic Stepanek enjoyed a straight sets triumph against Australian, Bernard Tomic. Stepanek will now face Spain's No. five seed David Ferrer in the next round.

No. 12 seed Gael Monfils had to work in order to earn a three- set triumph against Philipp Kohlschrebber 5-7, 7-6, 6-3 in a match where the Frenchman only showed his superiority in the final set.

Spain's Fernando Verdasco also progressed after the 15th seed defeated Istomin 7-5, 6-2.