After Rafael Nadal’s surprise defeat earlier in the weekto a German qualifier, it was the turn of Novak Djokovic to suffer unexpected defeatin Doha at the hands of the big serving Croatian, Ivo Karlovic. At 6 ft 11 in,the giant player has always been a dangerous opponent in the draw, but at35-years of age it had been thought that his best days were behind him, yet heutilised the awkward high winds at the Qatar Open to his advantage as hisopponent floundered and was unusually out of sorts on his fabled ground strokes.Twenty-one aces for the Croatian no doubt helped his cause as he turned aroundthe loss of the first set on a tie-break, to take the next two 7-6 6-4 to moveinto the semi-finals at the tournament.

Karlovic has been on the tour since 2000 and has earned asolid living out of the sport since then, but has never broken into the topten, with his highest ranking being 14 back in 2008. British Tennis fans may wellremember him reaching the quarter-finals there at Wimbledon 2009, which remainshis best performance at a Grand Slam event. Five ATP singles’ titles is perhapsscant reward for someone with his service power, as his matches frequentlyinvolve at least one tie-break due to the difficulty that many of his opponentshave in mastering his awkward service, coming as it does from such a hightrajectory.

With the top two seeds now both out, third seed Tomas Berdychof the Czech Republic now picks up the favourite’s tag, after he defeated France’sRichard Gasquet 6-2 6-1 to book his semi-final place against the ItalianAndreas Seppi.

Seppi had a tougher time against Ivan Dodig of Croatia, beforeclinching his match 7-5 6-4, and will need to find improved form to handle thepowerful Berdych one feels.

Karlovic will face the ever competitive, David Ferrer,after the consistent Spaniard had too much for the upcoming German Dustin Brown,losing only four games en route to victory.

World number two, Roger Federer also suffered a scare inhis match in the Brisbane International event on Thursday, before reaching the quarter-finalsthere. He lost the first set 6-4 to Aussie wildcard entrant John Millman beforebattling back to take the last two sets 6-4 6-3. The world number 153 was abreak up in the second set before the Swiss maestro began to take charge,breaking his rival’s serve twice to secure the levelling set and the result wasnever in doubt thereafter.

Federer played hisquarter-final match earlier today and was much more convincing, losing only onegame to another Australian, James Duckworth. He will now play the dangerous Bulgarian,Grigor Dimitrov in the semis, in a tournament where all of the top seeds madethe last four, as both Kei Nishikori and Milos Raonic both also came throughtheir quarter-final matches successfully. Raonic had the toughest test,eventually defeating Australian Sam Groth 7-6 3-6 7-6, and now faces Nishikoriin the other semi-final.