Novak Djokovic pulls out of Dubai Championships as Feliciano Lopez advances

Feliciano Lopez moved into the Dubai Championships semi-finals after Novak Djokovic was forced to withdraw from their quarter-final.

A below-par Djokovic informed the umpire of his decision after Lopez took the opening set 6-3 - but the world No 1 was clearly struggling with an eye condition and could not continue.

Lopez broke in the opening game of the match and Djokovic was forced to see the trainer after three games. Lopez held onto his advantage before a second break in the ninth game gave the Spaniard the first set, before Djokovic's dramatic exit.

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The Serb, a four-time champion in Dubai, had recorded the 700th win of his career earlier in the week but having chalked up 14 victories already this season, he was forced to pull out of the event.

Lopez is through to face Cyprus' Marcos Baghdatis, who was a surprise 7-5 6-0 winner over Spanish fourth seed Roberto Bautista Agut earlier in the day.

Earlier, Stan Wawrinka moved into a highly-anticipated semi-final against Nick Kyrgios with a comfortable 7-5 6-1 victory over Philipp Kohlschreiber.

The clash between Wawrinka and Kyrgios on Friday will be the first contest between the pair since their infamous match in Montreal last August.

Against Kohlschreiber, Wawrinka's three breaks proved enough to edge a topsy-turvy opening set that saw five dropped service games. The Swiss ace and second seed flew into a 2-0 lead, only for Kohlschreiber to bounce back with the next two before Wawrinka re-established his two-game lead to seize the initiative.

However, his German opponent fought back again to level matters before Wawrinka's crucial break in the 12th game of the match saw him clinch the opening set.

A more straightforward second set saw Wawrinka take control with his backhand beginning to find its range and he opened up a 4-1 advantage before a further break gave him a four-game cushion, which he rubber-stamped by winning five successive points from 0-40 down to hold serve and wrap up the match.

You can follow all the action from the Dubai Championships semi-finals on Friday, live on Sky Sports 3 from 1pm on Friday.