The Barloworld rider secured glory by the smallest of margins ahead of the peloton after a crash in the final kilometre brought a dramatic end to the Tour’s quickest stage so far this year.
Denmark’s Michael Rasmussen maintained his hold on the yellow jersey with nine stages remaining by finishing comfortably within the peloton.
However, the day all but ended the host nation’s chances of glory in Paris as Christophe Moreau, sixth in the overall standings at the start of the day, finished three minutes and 20 seconds behind the main group following a separate crash early on in the race.
He ended the day in 14th overall, more than six minutes off the pace.
Sprint specialist Erik Zabel also suffered a blow to his hopes of green jersey success by languishing well behind in the second peloton. Zabel’s misfortune has gifted Hunter an outside chance of overall sprint glory, but the South African was focusing on his stage victory after the race.
“I’m hugely happy,” he said. “I can’t even begin to explain what this means to me. It’s the sixth time I’ve ridden the Tour and I’ve given everything and been so close a few times.
“I really thought I had lost it again today but I found myself in a good position and gave it a lot of effort towards the end and I knew I would get to the finish. It does give me a chance to gain advantage on the green jersey but it will be difficult. Tom (Boonen) has got a decent lead but you never know what‘s going to happen and there’s a long way until Paris.”
The mostly flat 182.5km stage started in familiar fashion with several riders attempting to sustain a quick breakaway in the early stages before being reined in by a well-organised peloton who averaged a staggering 50.8km/h during the first hour of the race.
The decisive split appeared to have come with 99km remaining as Dmitriy Fofonov, Fabian Wegmann, Xavier Florencio and Philippe Gilbert attacked the group to try their luck.
The break prompted Great Britain’s David Millar to launch his own attack and within 15km the Flying Scot had joined up with the leaders to make it a five-man strong pack.
A mixture of apprehension from the peloton and effective teamwork from the breakaway group increased their advantage to over seven minutes with just 70km remaining.
But a staggering show of speed and determination in sweltering conditions from several rival teams in the peloton reduced their advantage to a mere two minutes within the space of 20km.
And they refused to let up as they reeled in all five riders with 38km left until the finish line in Montpellier.
Astana, Barloworld and Quickstep continued to lead an extremely high tempo from the front of the main group until 4km remaining when Alexandre Vinokourov attempted to catch everyone by surprise.
He was soon reined back in and as the peloton entered a tight final corner, several riders ended up thrown to the wayside after misjudging the harsh bend.
The confusion allowed Hunter to seize control and he crossed the line marginally ahead of former yellow jersey holder Fabian Cancellara.