Reigning champion Kei Nishikori has moved into the semi-finals of the Barcelona Open with 6-2 3-6 6-1 win over Spaniard Roberto Bautista Agut.

The Japanese is the heavy favourite to retain his title after Rafael Nadal’s shock defeat to Fabio Fognini on Thursday and impressively romped through the deciding set after being forced all the way for the first time this week.

Nishikori eased through the first set after breaking in the first game, but Bautista Agut responded by breaking for 4-2 in the second and held off three break points to serve out for the set.

The world number five upped his game in the third, though, as the depth and power of his groundstrokes forced Bautista Agut onto the back foot as Nishikori cruised through the final five games to take his place in the last four where he will meet Martin Klizan.

“In the second set he started to play well and I had to raise my level a little bit,” said top-seeded Nishikori.

“I concentrated really well in the third set, got ahead early and came through really strong in the end.

“I feel sorry for Rafa, but Fognini is a very tough player and there are plenty other good players in the draw like Klizan or David Ferrer.”

Slovakia’s Martin Klizan ended the hopes of veteran home favourite Tommy Robredo in straight sets 7-6 6-4.

Third seed Ferrer is also into the last four after he overcame some stiff resistance from Germany’s Philipp Kohlschreiber to win 6-3 7-6.

The Spaniard will play compatriot Pablo Andujar in Saturday’s semi-finals after he upset a flat Fognini 6-1 6-3 in just over an hour on court.