The power and precision of Isner and Mahut combined to produce a marathon Wimbledon encounter which emphatically rewrote the record books.
A transfixed crowd on Court 18 watched on as John Isner and Nicolas Mahut's tussle extended to a record 10 hours and 163 games without producing a winner as bad light ensured the first-round match will go into a third day.
Resuming just after 2pm after also being called off for bad light yesterday, neither player gave an inch on serve in a final set that ran to 118 games and also saw both players break the record for aces in a match - with Isner hitting 98 and Mahut 95.
With the score in the decider locked at 59-59 when play was suspended just after 9pm, the players will try for a result tomorrow.
In second-round action, Roger Federer again lived dangerously against an unfancied opponent before remaining on course to defend his title.
Ilija Bozoljac, a qualifier from Serbia ranked 152nd in the world, pushed the Swiss ace all the way in an absorbing match on Court One.
Federer, relegated from Centre Court for the first time for three years, triumphed 6-3 6-7 (4/7) 6-4 7-6 (7/5) and his serve was not broken throughout but it was his plucky opponent who earned most of the plaudits.
Third seed Novak Djokovic overcame the brutal serve of Taylor Dent to ensure a welcome early conclusion to the second match of his Wimbledon campaign.
The Serbian, whose first-round match on Monday broke the record for the tournament's latest finish, edged a tight first set that saw Dent's power amaze the Centre Court crowd before striding clear to secure a 7-6 6-1 6-4 triumph. He delivered one 148mph serve - another Wimbledon record.
Andy Roddick overcame an impressive start from Frenchman Michael Llodra to canter into the third round.
Roddick recovered from losing the first set in convincing fashion to triumph 4-6 6-4 6-1 7-6 (7/2) on Centre Court.
Nikolay Davydenko became the highest seed to crash out of the men's singles when he was beaten in four sets by Daniel Brands.
The seventh seed looked set for an easy ride against his 22-year-old German opponent when he won the opening set but Brands hit back to triumph 1-6 7-6 (7/5) 7-6 (10/8) 6-1.
Lleyton Hewitt enjoyed a straightforward passage into the third round as opponent Evgeny Korolev of Kazakhstan withdrew in the third set of their meeting on Court One.
The 2002 Wimbledon champion was leading 6-4 6-4 3-0 when Korolev called a halt to the encounter with an upper arm injury.
Gael Monfils, the 21st seed from France, will be Hewitt's next opponent after he defeated Slovakia's Karol Beck 6-4 6-4 6-7 (4/7) 6-4.
Spain's Feliciano Lopez, the 22nd seed, defeated Ricardas Berankis of Lithuania 7-5 4-6 6-3 6-4, while Yen-Hsun Lu of Chinese Taipei beat Poland's Michal Przysiezny 6-4 7-6 (9/7) 6-3.
There were also second-round wins for 12th seed Tomas Berdych, Jurgen Melzer, the 16th seed, 28th seed Albert Montanes, Victor Hanescu, Florian Mayer, Denis Istomin, Arnaud Clement and Philipp Kohlschreiber