Taylor Fritz and Joao Fonseca were made to wait to finish their second-round meeting at the Eastbourne Open on Wednesday as play was suspended due to darkness.
They will resume on Thursday locked at a set apiece, with top seed Fritz taking the opener 6-3 inside just 26 minutes before Fonseca hit back by edging the second set 7-6 (7-5).
The second-set tie-break saw Fritz move within two points of victory at 5-5, but Fonseca's sharp low volley took him to set point, an opportunity he did not pass up.
Thursday will be a long day for the winner of the match, as they must later return to the court to face Marcos Giron for a semi-final spot.
It was a mixed day for the seeds at Devonshire Park, with second seed Tommy Paul losing 6-4 3-6 6-3 to home favourite Dan Evans.
Third seed Jakub Mensik beat Reilly Opelka 7-5 6-3. The Czech will take on Spain's Alejandro Davidovich Fokina in the last eight, after he downed Jack Duckworth 6-7 (3-7) 6-3 6-4.
British lucky loser Billy Harris also advanced with a straight-sets win over Mattia Bellucci, with his reward a quarter-final matchup against fourth seed Ugo Humbert, who beat Lorenzo Sonego 7-5 6-4.
Data Debrief: Mensik follows Stepanek
While Fritz and Fonseca must sleep on their approach to winning a spot in the quarter-finals, Mensik has his place wrapped up already.
Considered one of the most promising youngsters on the ATP Tour, he is just the second Czech to reach the last eight at Eastbourne, after Radek Stepanek in 2011.
