Japanese second seed Kei Nishikori saved three match points to defeat South Africas Kevin Anderson 2-6, 6-4, 7-6 (8/6) on Thursday to reach the Geneva Open semi-finals.

Nishikori took his head-to-head record against Anderson to 4-1 and reached his first semi-final on clay this season as he builds towards the French Open which starts in Paris on Sunday.

"There haven't been too many times that I'm down match point and win, so it's great for me," said Nishikori.

"He had more chances, but I served a little bit better in the end. It's important to win some matches like this."

Nishikori next plays German qualifier Mischa Zverev who defeated US fifth seed Steve Johnson 6-4, 7-5.

Top seed Stan Wawrinka was down a set and an early break to a Sam Querrey before fighting back for a 4-6, 7-5, 6-2 victory.

The Swiss will next face Russia's Andrey Kuznetsov who saw off German lucky loser Cedrik-Marcel Stebe 6-2, 1-6, 7-5.