American John Isner and Frenchman Nicolas Mahut staggered off court as darkness fell on Wednesday after taking a chainsaw to the tennis record books on an unforgettable day at Wimbledon.

When darkness interrupted their first-round match for the second consecutive day with the score at 59-59 (yes, fifty nine - fifty nine) in the fifth set they had been hammering away at each other for an unbelievable 10 hours.

In a match of truly freakish proportions, towering 23rd seed Isner could barely stay upright as the crowds on Court 18 and those scrambling for every available vantage point chanted: "We want more...we want more".

Some even had the audacity to boo as the gladiators packed away their rackets but then broke out into spontaneous, rapturous applause as the realisation of what they had just witnessed sunk in.

The two players, providing they can revive themselves, will be back on Thursday to complete a mind-boggling match that brought Wimbledon to a standstill on Day Three and will become one of the great "I was there moments" in sporting folklore.

Until Wednesday the longest match occurred at the French Open in 2004 between Frenchmen Arnaud Clement and Fabrice Santoro -- that duel lasting a mere six hours and 33 minutes.

The fifth set alone of this mesmerising epic has lasted seven hours and six minutes and the way both players were serving suggested it might not even be concluded by close of play on Thursday.

To put things into perspective, Serena Williams spent only one hour more on court to win seven matches on the way to last year's Wimbledon title than Isner and Mahut did in their stupendous, energy-sapping, fifth set.

The previous longest singles match at Wimbledon was the five hours 28 minutes Greg Holmes needed to beat fellow American Todd Witsken in 1989.

Returning to court on a scorching day at Wimbledon delicately poised at two sets apiece after fading light had interrupted play on Tuesday, Isner and Mahut became embroiled in a brutal war of attrition in which the serve was king.

Mahut, who had to survive the qualifying tournament just to take his place in the first round, served to stay in the match an incredulous 55 times, and on each occasion the Frenchman did not flinch before calling for a time-out.

"I want to play on, but I can't see the ball," he told the umpire, who eventually halted proceedings.

Mahut fended off a match point at 9-10, two more at 32-33, then survived another one at 58-59 when he fired down a jaw-dropping 95th ace.

Isner sent down 98 bombs of his own as both players eclipsed the previous record of 78 aces by Ivo Karlovic in a Davis Cup tie against the Czech Republic last year.

Defending men's champion Roger Federer was shunted off the BBC's live transmission as the drama unfolded on Court 18 as two players who would normally be lucky to make their highlights show unwittingly grabbed the spotlight.

As shadows crept across the court and the sun dipped down below Wimbledon Hill the fifth set was finally curtailed after seven hours and six minutes -- the time it takes the International Space Station to orbit Earth four times.

"Nothing like this will ever happen again. Ever," American Isner gasped as he and Mahut left the court to a standing ovation.

"Someone has to win so we'll come back tomorrow," the 28-year-old Mahut, who looked the fresher player by the end, said.

"Everyone wants to see the end," he added.

Players who had already finished their matches were transfixed in the competitors' restaurant as the television channels were switched from the evening's World Cup fixtures to the events taking place just 200 metres away on Court 18.

"I walked on court at about 11-all in the fifth and now I'm off and they're still going," Federer told reporters after is second-round win against Ilija Bozoljac.

"This is absolutely amazing. In a way, I wish I was them, in some ways I wish I wasn't them. This is a very special match. I hope somehow this is going to end," he added.

Novak Djokovic could not take his eyes off the screen as he gave his press conference after a straight-sets defeat of Taylor Dent.

"It's unbelievable. You have to give them credit," he said. "Both of them are winners. Maybe they should agree on playing tiebreak if it's 50-50."

American Andy Roddick could not help himself.

"Seriously," he said on his Twitter site. "Doesn't anyone have to pee? Umpires included?"