The 6-7 4-6 6-4 6-3 9-7 victory by the ninth seed proved beyond doubt Henman's mettle at the French Open, where in the past he has come unstuck.
Not since Roger Taylor in 1973 had a Briton advanced this far in the heartland of claycourt tennis and Henman's win lifted him into his first Grand Slam quarter-final outside of Wimbledon.
"In terms of the atmosphere and the drama, that ranks pretty high," Henman said. "It's character-building that's for sure.
"It's a great atmosphere to play in. I just wanted to keep fighting as hard as I could to come away with a win and that's what I did. Through to the quarters... there's a lot of positives to take from that."
Henman's feat in reaching the last eight matches the achievement of his grandfather Henry Billington, who reached the same stage here in 1939.
The gloom for French fans deepened when Nicolas Escude pulled out of his match against third seed Guillermo Coria with an injured shoulder having lost the opening set 6-0.
France's Olivier Mutis had already been beaten 4-6 6-2 7-6 6-2 by Juan Ignacio Chela, the Argentine Henman plays next.
"It was amazing," Coria said. "Just one set... I was really surprised."
However, women's third seed Amelie Mauresmo provided some much-needed cheer for home fans. The Frenchwoman smashed Magdalena Maleeva 6-2 6-1 to reach the quarter-finals here for the second successive year.
Mauresmo has suffered from crippling nerves at her home Grand Slam in the past but on Sunday played a sublime match to line up a showdown with Russia's Elena Dementieva.
Ninth seed Dementieva pummelled former world number one Lindsay Davenport 6-1 6-3.
Women's second seed Serena Williams advanced in straight forward fashion.
Wearing a pink zip-up cropped-top, the American pulverised Shinobu Asagoe 6-3 6-1 to edge closer to a semi-final clash with her elder sister Venus. The fourth seed overcame Fabiola Zuluaga 6-1 7-6.
Serena must first beat seventh seed Jennifer Capriati, who saw off Italy's Francesca Schiavone 7-5 6-1 and picked up a minor leg injury in the process. Capriati beat Serena in the Rome semi-finals earlier this month.
DAMP DAY
The star of a blustery and damp day was undoubtedly Henman, though.
The Briton, whose artful style of play is seen as something of an anachronism in these days of baseline bludgeoners, had recovered from two sets down for only the second time in his career in his first-round
He has clearly got a taste for it and on Sunday saved a match point against Llodra before claiming victory on Court Suzanne Lenglen.
The 29-year-old sealed victory after four hours 11 minutes with a whipped forehand down the line to move to within three wins of his first Grand Slam triumph on a surface he detests.
Four-times a Wimbledon semi-finalist, Henman is locked at 2-2 in head-to-head meetings with Chela -- with one win apiece on clay.
While Henman advanced the hard way, Coria could hardly have had an easier passage.
The Argentine, the highest seed left in the men's tournament following the early exits of defending champion Juan Carlos Ferrero and American Andy Roddick, clinched the first set against Escude in 25 minutes before his opponent quit.
Coria, a semi-finalist last year, will next meet fifth-seeded Spaniard Carlos Moya, the 1998 champion, after he thrashed compatriot Tommy Robredo 7-6 6-4 6-2.
Like Coria, Mauresmo also had it easy. Her victory over 21st seed Maleeva was her easiest of the tournament and allowed her to equal her best performance at Roland Garros.
GREAT TENNIS
Following wins this season in the leading two claycourt tournaments before the French Open -- in Berlin and Rome -- Mauresmo has established herself as a favourite in her home Grand Slam.
"I just played a great tennis," Mauresmo said.
"I felt that my game again is getting better and better as the matches are going... I made it probably look easy."
First she will have to overcome ninth seed Dementieva, who was in cracking form against Davenport.
She was in charge from the start and Davenport, with a sore right knee taped, quickly slumped out of the only Grand Slam she has yet to win.
"I mean, it was, you know, the kind of day that Americans don't like to play on clay anyways," Davenport said. "It was very heavy... I just wasn't feeling great."
Dementieva was joined in the last eight by two other Russians, Maria Sharapova and Anastasia Myskina.
Sharapova has yet to drop a set in the tournament and she swept aside Marlene Weingaertner 6-3 6-1 while Myskina beat Svetlana Kuznetsova 1-6 6-4 8-6.