John Isner has the chance for a second successive Miami Open title after the defending champion hitting 21 aces to beat Canada’s Felix Auger-Aliassime 7-6 (7-3), 7-6 (7-4) in the semi-finals.

The 33-year-old now has an unbeaten streak of 11 victories in Miami after lifting his maiden Masters title last year with a win over Alexander Zverev.

Auger-Aliassime, who at 18-years-old is the youngest semi-finalist in Miami’s 35-year event history, broke the Isner serve in both sets on Friday.

However, costly mistakes allowed Isner to enter two tie-breaks where the American dominated to improve his tie-break tally to 12 wins and only one loss in Florida.

Isner will face either three-time champion Roger Federer or another Canadian teen Denis Shapovalov in Sunday’s final.

After recovering an early break, Isner entered familiar territory in the tie-break, where he has won seven sets by that method en route to the final four.

“All my matches have been very similar scorelines but I’m very happy to be back in the finals,” said Isner.

“I can’t say enough good things about Felix, he’s humble, he works hard and I think he can go all the way to the top.”

Isner distanced himself from Auger-Aliassime with a 5-3 tie-break lead before winning a rally to continue his run in this year’s tournament without dropping a set.

Teenage qualifier Auger-Aliassime, who will be the first player born in 2000 to enter the top-50 in the rankings on Monday, broke Isner’s intimidating serve to lead 4-2 in the second set.

However, Isner responded immediately to recover the break and level for 5-5 with a quickfire ace.

And after a quick one-two punch from Isner with a strong serve followed by a winner another tie-break was opened.

Isner won three straight points before firing down a final ace, capping his match total at 21, to complete the match in one hour and 53 minutes.