Top seed and world number five David Ferrer struggled into the semi-finals of the Malaysian Open when he defeated Dutchman Igor Sijsling 4-6, 6-3, 6-4 on Friday. The Spaniard, who only started his campaign in the tournament on Thursday after receiving a first round bye, was sluggish at first in the game against Sijsling, who this week fell 15 places to number 97 in the world rankings. He lost serve once in each of the three sets at the Putra Stadium on the outskirts of the capital Kuala Lumpur. But he said overall he was happy with his play in the ATP 250 tournament. \"It was such an incredible game with some good rallies,\" he said. \"I\'m happy to have gone through to the semi-finals as I had to play well in the last two sets.\" In the semis, he will now meet seventh seed and world number 34 Julien Benneteau of France, who smashed Alejandro Falla of Colombia 6-2, 6-2 earlier Friday. \"I\'ll take it easy, have a good rest and try to go out and give the crowd a great performance in the semi-finals,\" Ferrer said of his next game. Meanwhile, Russia\'s Nikolay Davydenko, the former world number three and winner of the inaugural Malaysian Open in 2009, retired from his quarter-final against Kei Nishikori after suffering a muscle injury in his left leg. Davydenko, who has dropped to number 44 in the world, had lost the first set against the third seeded Japanese 6-4 before calling it quits. In the semis, Nishikori, who at number 17 is the highest ranked Asian in the world, will meet second seed Juan Monaco of Argentina. \"Now that I have qualified for the semi-finals, my thoughts are on my opponent and close friend Monaco,\" the 22-year-old said. \"I have been practising with him since we arrived in Malaysia. I expect a difficult match as we know each other\'s game very well... He likes to play from the baseline so I will have to adjust my game plan accordingly.\" In an earlier match, world number 11 Monaco easily defeated Canadian Vasek Pospisil 6-3, 6-4.