Top seed Kei Nishikori survived a tough slog against unheralded opponent Carlos Berlocq before winning his semi-final match at the Argentina Open on Saturday.

The Japanese world number five took nearly three hours to overcome local wild card Berlocq 4-6 6-4 6-3 on the clay surface in Buenos Aires.

In a match that featured 24 break points, Nishikori was slightly more successful, converting four of his 14 opportunities against the world number 77.

Nishikori will face in-form Ukrainian Alexandr Dolgopolov in Sunday's final.

"It's really nice to be in a final again because I had a couple tough years," said Dolgopolov, who will be playing in his first title match in three years

World number 66 Dolgopolov continued his barnstorming run through the tournament, beating fourth seed Pablo Carreno Busta of Spain 7-5 6-2 in the other semi.

Nishikori has a 5-0 career record against Dolgopolov, who has not dropped a set the entire tournament.