Nick Kyrgios' quest for a third ATP title of 2016 remains on course after he cruised past Gilles Muller with an assured display at the Japan Open on Friday.

The Australian - seeded sixth in Tokyo - was rarely troubled in his 6-4 6-2 quarter-final victory, with Kyrgios only dropping four points on serve as he maintained his record of not being broken this week.

Muller's serve was also impressive but he was broken on three occasions as Kyrgios wrapped up a straight-set triumph.

"I thought I played great today," said the 21-year-old. "I served well, returned well and my engagement level was really good the whole time."

Kyrgios will meet Gael Monfils in the semi-finals after the Frenchman edged two tie-breaks against Ivo Karlovic, the second seed progressing after a 7-6 (8-6) 7-6 (8-6) victory.

In a match dominated by the serve it was Monfils who raised his game when it mattered, converting his second match point to send Karlovic packing.

Karlovic's compatriot Marin Cilic had no problems booking his last four spot, though, as he beat Juan Monaco 7-5 6-1 in 80 minutes.

His next opponent will be fifth seed David Goffin - who has won the previous two meetings with Cilic - after the Belgian came from a set down to oust Joao Sousa.

Goffin started slowly but eventually found his range late in the second set with a string of crisp winners on his way to a 1-6 7-5 6-2 win.