World no 1 pulls out with eye problem

World number one Novak Djokovic was forced to retire from his quarter-final with Feliciano Lopez at the Dubai Tennis Championships because of an eye problem.

Djokovic lost the first set against Lopez 6-3 on Thursday, and decided he could no longer continue after consulting with his medical team.

It was Djokovic's first retirement since 2011, and ends his run of reaching 17 consecutive finals.

Speaking to reporters, Lopez claimed Djokovic was struggling with an eye infection.

"It's very sad when one of the greatest players ever has to retire from a match like that," he was quoted as saying by the BBC.

Spaniard Lopez will face Marcos Baghdatis for a place in the final of the ATP 500 event after the Cypriot defeated Roberto Bautista Agut 7-5 6-0 on the outdoor hard courts of the Aviation Club Tennis Centre.

Earlier, Nick Kyrgios continued his good form with a straight-sets win over Tomas Berdych, his second victory against the Czech in the space of six days, after beating him in the semi-finals en route to claiming his first ATP title at the Open 13 in Marseille last week.

The Australian won 6-4 6-4, breaking Berdych once in each set to book a semi-final against Stan Wawrinka, who overcame Philipp Kohlschreiber 7-5 6-1.

It remains to be seen if Kyrgios will be fit enough to cope with the two-time grand slam winner, having struggled with a back problem on the way to his eighth successive victory.

"I was in pain at the start, I've played a lot of matches in a row now," he said.