Sebastian Korda won the battle of the young Americans as he beat Ben Shelton to reach his first ATP Masters 1000 semi-final in Shanghai.

Korda recovered from a set down to win 6-7 (10) 6-2 7-6 (6) in a clash lasting two hours and 55 minutes.

It was the first all-American quarter-final at a Masters 1000 event for six years and it did not disappoint, with the explosive Shelton finally taking his fifth chance to win the opening-set tie-break having earlier failed to serve it out.

Korda hit back strongly and Shelton appeared to be flagging physically when he trailed by a break in the deciding set.

But he fought back to level and saved five match points from 1-6 in the deciding tie-break before Korda clinched his sixth opportunity.

“It’s super cool,” said Korda. “I played a really high level. Ben did as well. We had a lot of great points out there and hopefully it’s the first of many battles that we play against each other. He’s such an electric tennis player and it was a lot of fun to share the court with him today.”

In the last four, Korda will take on 16th seed Hubert Hurkacz, who ended the surprise run of Hungarian Fabian Marozsan with a 4-6 6-1 6-3 victory.