Alexandr Dolgopolov has recorded his third consecutive straight-sets win to advance to the last four of the Mexican Open at the expense of Ivo Karlovic.

There was only one break in a match between two big servers and it was Dolgopolov who claimed it in the fifth game of the first set.

He had previously wasted three break points as Karlovic battled to stay with an opponent who is positioned 17 places above him in the world rankings.

The Ukrainian dropped only four points on his own serve until the final game of the opener, when he had to save a break point before rallying to take the first set after 37 minutes of play in Acapulco.

Games were then exchanged without the threat of a break until the eighth game of the second, where Karlovic missed out on two opportunities to move ahead in the set with errors that would later prove costly.

The set went to a tie-break and Dolgopolov was again imperious on serve, securing a 6-4 7-6(4) victory and a semi-final clash with the winner of Ernest Gulbis versus Grigor Dimitrov.