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

The Japanese world No. 5 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 77th-ranked player.

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 No. 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 in the entire tournament.