Nishikori downs Cilic to reach Barcelona semis
File picture shows Kei Nishikori of Japan hitting a backhand to Marin Cilic of Croatia at the Brisbane International on January 3, 2014 - by William West
Nishikori, seeded fourth, was ruthless in the opening set as he broke the big Croat's serve three times.
The second set was more of a contest, but the world number 17 still had too much as he sealed victory in just over an hour to register his best ever run in Barcelona.
Next up for Nishikori will be a meeting with Latvian Ernests Gulbis after he secured a third semi-final appearance of the season with a 6-1, 6-4 win over Russia's Teimuraz Gabashvili.
Top seed Rafael Nadal will continue his quest for a ninth title in the Catalan capital when he faces fellow Spaniard Nicolas Almagro later on Friday.
Germany's Philipp Kohlschreiber meets Santiago Giraldo in the other quarter-final.