Roger Federer gained a measure of revenge against Wimbledon nemesis Kevin Anderson, beating the South African 6-0 6-4 at the Miami Open on Thursday to set up a mouthwatering semi-final against a player barely half his age.
Isner is to face Canadian teen sensation Felix Auger-Aliassime in the last four.
He will meet Shapovalov, who beat fellow young gun Frances Tiafoe 6-7, 6-4, 6-2 to reach his third ATP Masters semi-final.
Defending champion John Isner reached another Miami Open final by ending Canadian teenager Felix Auger-Aliassime's historic run.
Ashleigh Barty needed all day to book her spot in the biggest final of her career at the Miami Open.
Isner arrived in the match having won all nine of his tiebreaks faced in the tournament and maintained that ideal run to gain the initiative in the contest after the first set.
"I have been here for 12 hours today and I'm really happy with the way I was able to come out after the rain delays and kind of get on the front foot pretty early", said Barty, who has three career titles. "But if I do it, I will be very proud". No, seriously, I'm going to go out and enjoy myself. They're really good players, and really good people, too. It was nerves. I couldn't get a second serve in. He started with a three-set win over Jaume Munar and then defeated Joao Sousa and Jordan Thompson in straight sets. Conversely, Isner has played 11 Masters semi-finals, winning four, although only twice was he a pre-match favourite - once against Richard Gasquet in Toronto in 2012 and also against Filip Krajinovic in Paris in 2017.
Auger-Aliassime, aged 18 and 233 days, is the youngest man in the tournament's 35-year history to reach the last four, having beaten a 14-year record set by Spanish 17-time major victor Rafael Nadal.
Federer, a victor of 100 career titles, can look back on dozens of brilliant performances and the Swiss maestro could add his ruthless fourth-round win over the red hot Russian to that list.
"I can go in there and play with freedom and try to play my best tennis", Barty said.
There were only 27 minutes on the clock when Federer, whose backhand slice in particular was causing Anderson all manner of problems, broke in the first game of the second.
Isner, 15 years older and six inches (15.24 cm) taller than his rival, had only been broken twice in 48 service games at Miami and it wasn't long before the youngster realized what makes his booming serve so hard to break down.