Martin Klizan has advanced into the semi-finals of the Barcelona Open courtesy of a 7-6(5) 6-4 victory over Tommy Robredo.

Both players struggled to break down one another's serve and eventually a tie-break was needed to separate the two competitors.

Klizan was able to edge the set decider 7-5, and he continued his dominance on the clay surface by going a break up in the early stages of the second set.

Robredo came close to breaking back immediately, but he squandered the opportunity, and Klizan managed to see out the set to push himself into a semi-final tie against Kei Nishikori.