(Reuters) - Reigning champion John Isner twice fought back to end Canadian teenager Felix Auger-Aliassime's run at the Miami Open with a 7-6(3) 7-6(4) win in the semi-finals on Friday.
American Isner overcame 3-5 deficits in both sets to set up a final clash against either Swiss Roger Federer or Canadian Denis Shapovalov on Sunday.
Federer and Shapovalov will play their semi-final later on Friday.
Auger-Aliassime's failure to close out either set on his serve was key to the outcome of the match.
(Reporting by Gene Cherry in Raleigh, North Carolina; Editing by Toby Davis)