Considered one of the best servers ever to play on the ATP Tour, Isner achieved his career-high singles ranking in July 2018 by virtue of his maiden Masters 1000 crown at the 2018 Miami Open and a semifinal appearance at the 2018 Wimbledon Championships.
requiring five sets and 183 games to defeat Nicolas Mahut in a match which lasted 11 hours and 5 minutes, and was played over the course of three days.[3] Isner holds the record for hitting the ATP's fastest "official" serve ever and third-fastest on record in tennis at 157.2 mph or 253 km/h during his first-round 2016 Davis Cup match.
Then again, when you have two players on a par with each other, we can expect it to go on somewhat longer, and if we’re talking about a major tournament like Wimbledon, then we could be taken into a fifth set and significantly longer viewing time.