Germany's Zverev is through after coming from a set behind to beat Borna Ćorić of Croatia, while American Brady bettered Yulia Putintseva.

Brady has never gone this deep at a Grand Slam before, while a semi-final appearance equals Zverev's best showing at a Grand Slam and is his best US Open result already.

Playing in the showcase Arthur Ashe Stadium, 25-year-old Brady made light work of Kazakhstan's Putintseva and won 6-3, 6-2 in less than 70 minutes.

Brady hit 22 winners compared to Putintseva's seven and broke Putintseva's serve on five occasions, making the fact she herself was broken twice redundant.

Either 2018 champion Naomi Osaka of Japan or fellow American Shelby Rogers will be Brady's opponent in the last four.

Brady won her first Women's Tennis Association Tour event last month - the Top Seed Open in Kentucky - and is the 28th seed at Flushing Meadows.

By contrast, Zverev is the fifth seed in the men's singles and one of the favourites for the title now that the top seed is out and a new Grand Slam winner guarenteed.

Despite his higher seeding, Zverev had lost three of his four previous matches against Ćorić and losing the opening set 6-1 will only have added to the nerves.

The German showed resilience to win each of the next two via tiebreak, however.

Ćorić then had four break points in the fifth game of the fourth set, but could not convert and Zverev went on to claim a 1-6, 7-6 (7-5), 7-6 (7-1), 6-3 win and reach a second successive Grand Slam semi-final.

Zverev's serve was capricious and he produced 12 double faults to go with 18 aces, but his first serve landed in 71 per cent of the time.

Canada's Denis Shapovalov and Pablo Carreño Busta of Spain play later today for a place in the semi-finals against Zverev.