Frances Tiafoe was an impressive winner of his quarter-final matchup against Brandon Nakashima in Friday's action at the Atlanta Open, cruising in straight sets 6-4 6-2.

Tiafoe, the fourth seed, was in control throughout, capitalising on a pair of double faults in the first set to grab the early break. 

He also had a clear advantage with his second serve, winning 76 per cent of those opportunities (13-of-17) compared to 36 per cent for Nakashima (five-of-14).

Tiafoe will play Jenson Brooksby in the semi-final after he defeated big-serving 37-year-old John Isner 3-6 6-1 6-4.

Isner's serve was uncharacteristically vulnerable after the first set, winning 90 per cent of his successful first serves in the opener, before that number plummeted to 46 per cent in the second, and 59 per cent in the last.

Ilya Ivashka pulled off the upset of the day by knocking out fifth seed Tommy Paul, continuing a terrific run of form. Ivashka is now 7-3 from his past 10 matches, with his three-losses coming against superstars Stefanos Tsitsipas and Daniil Medvedev (twice).

He will play Australian Alex de Minaur in the other semi-final after he came from a set behind to run over the top of Adrian Mannarino 4-6 6-3 6-0.

Mannarino showed he has what it takes to compete with a top-30 talent like De Minaur, but the 34-year-old simply ran out of gas towards the end of the second set.

In the deciding set, De Minaur won 70 per cent of his points on serve (14-of-20) and 72 per cent of his return points (13-of-18).