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Diallo pushed De Minaur all the way in the first set, but the Australian eventually prevailed 7-6 (10-8) 6-3 in just over two hours.

The pair traded breaks twice in the first set, with neither able to gain a proper advantage as they went all the way to the tie-break.

De Minaur then raced into a 5-3 lead, but Diallo clawed his way back into the match to take the lead before failing to convert two set points.

The top seed then had to dig in deep in order to get a vital break to take a 3-1 lead in the second, eventually converting his fifth break point in the marathon 15-minute game.

From there, he remained in control, though Diallo held off two match points to claw back to 5-3, but De Minaur got over the line in the next game.

Earlier in the day, Adrian Mannarino claimed his 77th tour-level victory on grass as he defeated Jakub Mensik in three sets.

The Frenchman claimed a 5-7 7-6 (7-3) 7-6 (7-5) victory over the 20 year-old to book a meeting with Arthur Fery in the last 16.