Ben Shelton and Frances Tiafoe continue their quest to become the first American men's Grand Slam champion since Andy Roddick's 2003 triumph at Flushing Meadows as the US Open reaches its semi-final stage.

Shelton sent defending champion Carlos Alcaraz packing in the early hours of Wednesday in the latest-finishing match in tournament history, reaching his third major semi-final. "That was a war," said Shelton. "The most enjoyable match that I've had in my career."

Tiafoe recovered from two sets and a break down to beat compatriot Alex Michelsen, reaching the semi-finals for a third time. "I'm just a different person in general," said Tiafoe. "I'm excited to see what this me does."

Former world No 1 Lindsay Davenport said: "If you hear their stories about last fall, and what a dark place Frances was in, he was willing to turn over, to try and give it his best shot."