Do not discount him as we enter the second half of the year.
Isner has yet to be broken at this year's tournament and saved the only break point he faced on Wednesday.
Raonic has the fastest serve of this year's Wimbledon at 147 miles (236.5 kilometres) per hour, while Isner is just behind on 144mph (231.7kph).
Bethanie Mattek-Sands' return to Wimbledon won't get a flawless ending.
Serving at 5-6, Anderson fell behind Love-30, which put Federer two points form defeat.
"Sure, it's disappointing losing the next two sets after winning the first two and having match points".
"I think you always sort of are learning as you go along".
Even if Federer had managed to get past Anderson, as he nearly did, having held match point in the third set, there was no guarantee he would have gone on to win the title, especially with a rejuvenated Novak Djokovic in the other half of the draw, not to mention Rafael Nadal and Juan Martín del Potro.
This loss was all the more shocking given Federer's resurgence since the start of 2017, rising from No. 17 in the world (his lowest rank since 2001) to become the oldest No. 1 in history at age 36 while winning three Grand Slam titles (his first since 2012).
"In the last set there was a little of everything, great points, great rallies, he was hitting insane with his forehands".
Anderson is the first South African man to make the last 4 at Wimbledon since Kevin Curren in 1983.
Federer has won his six previous five-set matches.
It wasn't till the end of the third set, however, that Anderson's resolve came into play.
It will be the 31-year-old Serb's first semi-final at a Slam since the 2016 French Open when he completed the career Grand Slam.
Tokozile Xasa hailed Anderson as a true ambassador of the country after he pulled off one of Wimbledon's biggest upsets on Wednesday, beating Roger Federer to advance to the semifinals.
But after failing to convert a match point in the third set, Federer allowed a rash of errors to creep into his game, particularly on the forehand side.
There wasn't the faintest warning that the match would turn into a cliffhanger, with Federer sauntering through the first with customary balletic ease.
The Swiss maestro had a match point in the third set against South African behemoth Kevin Anderson, but couldn't maintain the high-quality tennis that had led him to the final eight and he ended up being bundled out in five sets.
Roger Federer is ready to take notes from Sachin Tendulkar after his nifty piece of forward defence at Wimbledon caught the eye of the cricket legend.
Federer won the first two sets, 6-2, 7-6 (5) before Anderson rallied to win the next two sets, 7-5, 6-4, becoming the first player at Wimbledon this year to take a set from Federer.
The setting was not the only thing alien to the defending champion.
"I don't know why Del Potro shouldn't think he has a great chance", Wilander said.
The 20-time Grand Slam champion appeared to be moving towards his 5th successive Wimbledon semifinal after taking the opening two sets.
Additionally, if you can't watch live, you can get 50 hours of cloud DVR storage as an additional add-on when signing up for your free trial. Federer may well be the greatest of all time but even he will find it tough to win at that age.
"Sorry to Juan Martin, he's an awesome opponent and player". Before this tournament, Isner had made the quarterfinals only once before - in 2011's US Open when he was bounced in the quarterfinals.