Bulgarian star Grigor Dimitrov returned to TEB BNP Paribas Istanbul Open with a struggling 7-5, 4-6, 7-5 win over qualifier Adrian Ungur.

Despite getting broken in the fourth game, Dimitrov managed to delete this disadvantage immediately in the next game before turning things around in the 11th game. 2nd seed Dimitrov broke Ungur to take the lead, then made no mistake as he closed the first set 7-5

World no.194 Ungur maintained his fighting performance in the second. Leading 5-4 on Dimitrov’s serve, Romanian qualifier Ungur stepped forward at the crucial moment to catch the break for 6-4 and levelled the sets.

Deciding set was another combat for Dimitrov. While serving at 4-5 and two points to get knocked out at 30/15, Dimitrov held his nerves and stayed in the match. In the next game, Grisho came up with a critical break before finishing the nail-biting encounter with a love serve game.

After 2 hours and 14 minutes of duty, highlighted by classy backhand rallies from the baseline on the Garanti Koza Arena, former no.8 Dimitrov survived the scare and reached the last eight at the TEB BNP Paribas Istanbul Open.

Dimitrov will next face 6th seed Jiri Vesely in the quarterfinals. Vesely, who started his Istanbul campaign with a straight-sets win over Thiemo de Bakker, beat Spaniard coeval Roberto Carballes Baena 6-7, 6-2, 6-2 in 2 hours and 25 minutes.