World number three Novak Djokovic powered his way to a 7-6 6-2 win over unseeded Croat Mario Ancic to book his place in the semi-finals of the Madrid Masters on Friday. The 20-year-old Serb became the first player to take a set off Ancic this week when he took the opener on a tie-break, but then twice broke his opponent's serve in the second to run out a comfortable winner.
Djokovic will face the winner of quarter-final showdown between home favourite Rafael Nadal and Argentine David Nalbandian in the last four. Defending champion and world number one Roger Federer takes on Spanish wild card Feliciano Lopez and last year's losing finalist Fernando Gonzalez meets Nicolas Kiefer in the other quarter-finals.
Ancic, who missed six months of the season through illness and disposed of sixth seed James Blake on his way to the quarters, put Djokovic under immediate pressure on the ultra-fast surface but failed to take advantage of three break points in the opening game.
Djokovic then found his rhythm and with both players staying strong on their serves the set boiled down to a tie-break. The Serb, who has won five titles in his breakthrough season, earned himself a mini-break with a superb lobbed winner and got another with a sharp net volley to take the set.
He went over on his left ankle and had to receive courtside treatment in between sets but appeared to suffer no ill-effects from the incident. Djokovic had to save three more break points on his first service game in the second set but hit back hard to break the Ancic serve and repeated the feat in the fifth as he cruised to an emphatic win.