John Millman saved nine break points to beat off the challenge of Swede Elias Ymer 6-2 7-6 (10-8) to reach the round of 16 at the at the ATP Citi Open in Washington.

Millman will face big-serving American Reilly Opelka for a spot in the quarter-finals.

But there was no joy for fellow Aussie Alex de Minaur, who took the first set against American Steve Johnson but but then fell away, going down 6-7 (5-7) 6-4 6-2.