Top seed Jessica Pegula bowed out of the Libema Open following a three-set defeat by Aleksandra Krunic in s'Hertogenbosch as Alex De Minaur reached the quarter-finals of the competition in the Netherlands. 

World number five Pegula was ousted 7-6 (7-3) 6-7 (3-7) 6-4 by the 2018 winner of this event, who claimed the fifth top-10 victory of her career and advanced to the quarter-finals in the women's singles.

Now ranked 400th in the world, Krunic recovered from an earlier break in the opening set to force a tie-break, in which she won five straight points to draw first blood.

Krunic also cancelled out a break before heading into another tie-break, but Pegula reeled off five points on the spin this time to level.

The American was appearing in her first tournament since April, having missed the European clay-court season with a rib injury.

However, she saw two break-point opportunities go begging in the opening game of the deciding set, and Krunic crucially broke in game three before holding out for an impressive victory against the top seed.

Later in Thursday's play, De Minaur booked his place in the quarter-finals of the competition after a straight-sets victory over Zizou Bergs in the men's singles. 

The world number nine had to work for his victory over the Belgian, overcoming his opponent 7-5 6-4 to earn his first triumph on a grass court this year. 

Bergs bettered his opponent in the opening exchanges and raced into a 4-1 lead, but De Minaur would eventually prevail in the first set, breaking twice and following up without dropping a point on serve in the final game. 

The Australian would again endure a difficult set to confirm the victory as Bergs threatened to level the encounter, but the number one seed again showed his class, finishing the contest in style. 

De Minaur will face either Roberto Bautista Agut or Milos Raonic in the next round.

Data Debrief: Krunic rekindles special memories 

Krunic will forever have an affinity with s-Hertogenbosch, where she won her only career WTA title six years ago.

And the 31-year-old claimed an impressive scalp here to reach her first WTA quarter-final since 2022 - and first on grass since that 2018 triumph.

De Minaur impressed once again in the men's singles, winning 86 per cent of his first serve points against Bergs. 

Their meeting was the first between the pair, with De Minaur able to bounce back from his quarter-final defeat to Alexander Zverev at the French Open.