Top seed Marin Cilic booked his place in the quarter-finals of the ABN Amro World Tennis Tournament with a 6-1 2-6 6-4 victory over fellow Croatian Borna Coric in Rotterdam.
After coasting through the opening set, the world number seven found himself trailing 4-2 when broken in the second set, before then losing serve again as Coric rallied.
Any hopes of an upset, though, were ended as Cilic finally forced a breakthrough in a lengthy game seven of the deciding set and went on to close out victory in just under two hours. He will next face sixth-seeded Frenchman Jo-Wilfried Tsonga.
Third seed David Goffin is also through after the Belgian came from behind to beat Dutchman Robin Haase 5-7 6-4 6-4.
Number four seed Tomas Berdych saw off Frenchman Richard Gasquet, the Czech player winning 7-6 (7/4) 6-1.
Thursday's late matches saw victories for both number two seed Dominic Thiem and Grigor Dimitrov.
Austrian Thiem came through in straight sets 6-4 7-6 (7/4) against Gilles Simon of France, while it was a similar story for fifth-seeded Bulgarian Dimitrov as he saw off Denis Istomin of Uzbekistan 7-6 (9/7) 6-1.
Dimitrov will meet Goffin for a place in the semi-finals while Thiem will take on French qualifier Pierre-Hugues Herbert.
At the ATP Argentina Open in Buenos Aires, Uruguay's number two seed Pablo Cuevas suffered a surprise early exit as Ukrainian Alexandr Dolgopolov claimed a 6-3 7-6 (7/4) victory in their second-round encounter.
Gerald Melzer of Austria is also through after a 7-6 (7/4) 6-3 win over Buenos Aires-born Guido Andreozzi.
Third seed David Ferrer is out, losing to home wildcard Carlos Berlocq 6-4 6-2, while fellow Spaniard Tommy Robredo was beaten 6-3 6-4 by Thiago Monteiro.
In the Memphis Open, top seed Ivo Karlovic was beaten in straight sets by Nikoloz Basilashvili in the second round.
The world number 20 had no answer to Basilashvili's serve - the Georgian winning every point when he got his first serve in - and suffered a 7-6 (7/2) 6-3 defeat.
Fourth seed Steve Johnson is through to the quarter-finals after beating fellow American Tim Smyczek 3-6 6-4 6-2.
Johnson will face Mikhail Kukushkin in the last eight after the world number 103 beat qualifier Darian King 6-3 6-0.
Australian qualifier Matthew Ebden completed the quarter-final draw by beating Taylor Fritz in the day's last game.
The world number 490 saw off his American opponent 6-4 4-6 6-3 to set up a last-eight clash with Basilashvili.