Tommy Paul is into the last four at a grand slam for the first time after overcoming surprise package Ben Shelton in an all-American quarter-final at the Australian Open.

Paul triumphed 7-6 (8-6) 6-3 5-7 6-4 against Shelton at Rod Laver Arena, ending the 20-year-old's surprise run on his first trip outside the United States.

World number 35 Paul showed his class in longer exchanges between the two big-serving Americans, though Shelton briefly troubled the 25-year-old when he claimed the third set after going a break down.

Having found an immediate break to quell Shelton's momentum, Paul dominated on serve in the fourth set to become the first American man to reach the Australian Open semi-finals since Andy Roddick in 2009.

Having teed up a meeting with either Novak Djokovic or Andrey Rublev, Paul said: "Yesterday when I was doing a couple of interviews, they asked how it felt to be in the quarter-finals, and I was like, 'semi-finals sounds a little better'.

"I'm pumped to be there and really excited for whoever I play. Making it to the second week of a slam is everyone's dream when they start playing tennis. So I can't believe I'm here right now."

Data slam: Paul dominates on serve

Having originally appeared to be on course for a straight-sets triumph, Paul could have lost his way when Shelton claimed the third set, but the 25-year-old was outstanding on serve to see it through.

Paul won all 17 of his first-serve points in the final set, winning 86 per cent throughout the match as his quality told.

ACES/DOUBLE FAULTS

Paul – 7/3
Shelton – 24/6

WINNERS/UNFORCED ERRORS

Paul – 43/26
Shelton – 42/50

BREAK POINTS WON

Paul – 3/15
Shelton – 2/4