Alexander Zverev said he was very satisfied with his performance, describing it as a major improvement on his previous matches. (AFP pic)SHANGHAI: Top seed Alexander Zverev took "a huge step up" to dismantle Alex de Minaur 6-4, 6-4 on Thursday and roll into the Shanghai Masters semi-finals.

He will play Alejandro Davidovich Fokina, who advanced when France's Arthur Gea retired injured from their quarter-final after 22 minutes.

Zverev, who will end the year at world number one, was tested by the Australian's speed in the first set but sent down a string of dazzling forehands to convert a break point in the fifth game.

Despite a double-fault the German saved three break points in a row to hold serve and was rewarded in the 10th game, taking the first set with a buttery backhand at the net.