HALLE, Germany -- Defending champion Borna Coric outlasted Portuguese qualifier Joao Sousa 7-6 (4), 5-7, 7-6 (4) to reach the quarterfinals of the Halle Open on Wednesday.
Coric, who defeated Roger Federer in last year's final, saved seven of the nine break points he faced and took his match point after a 26-shot rally to beat Sousa in just under 3 hours.
The 14th-ranked Coric next faces France's Pierre-Hugues Herbert, who earlier defeated Ukrainian qualifier Sergiy Stakhovsky 2-6, 7-6 (2), 6-4 in their second-round match.
Karen Khachanov defeated home favorite Jan-Lennard Struff 6-3, 3-6, 6-4 at the grass-court tournament, a warm-up for Wimbledon.
Khachanov, ranked a career-high No. 9, hit 11 aces and converted two of his seven break chances to win in 1 hour, 43 minutes. The Russian will next face an Italian, Stuttgart Open champion Matteo Berrettini or Andreas Seppi.
David Goffin defeated Radu Albot 4-6, 6-4, 6-3 and awaits the winner between the second-seeded Alexander Zverev or American Steve Johnson, who play on Thursday.
Nine-time champion Federer also returns Thursday against Jo-Wilfried Tsonga of France. Tsonga won their only previous match on grass, at Wimbledon in 2011.