Cheered on by residents who flashed "V" for victory signs and chanted Allahu Akbar (God is greatest), the troops loyal to the National Transitional Council (NTC) massed early morning in Misrata and then rolled out of the port city.
The convoy comprised of heavy artillery and pickup trucks loaded with machineguns, rocket launchers and Katyusha rockets, and its fighters were well stocked with food, water and ammunition.
But roadside support dropped off as the convoy headed through villages towards Sirte, with children and teenagers running alongside but adults standing further back with arms folded and showing little emotion.
The convoy split up at the desert town of Abu Qurin, from where one of its commanders said they would approach Sirte from three directions in a pincer movement.
"We are turning the tables on Gaddafi. We were attacked in Misrata on three fronts, and now we're going to attack Sirte on three fronts," said Fawzy Sawawy, head of the Mountains Brigade.
As they headed farther to the east, an AFP correspondent received unconfirmed reports that NATO struck a south-bound convoy of pro-Gaddafi armoured vehicles about 50 kilometres (30 miles) from Sirte.
The rooftops of vehicles in the Misrata convoy were painted yellow and red in an apparent signal to NATO that they are not Gaddafi's forces.
While wary of mercenaries, the young men in the convoy expressed confidence of overcoming the pro-Kadhafi forces in Sirte thanks to their combat experience in the devastating, months-long battle for Misrata.
"Misrata's forces are among the strongest and most experienced," Mohammed al-Gawi, a 24-year-old in the convoy, told AFP.
Another Mountains Brigade fighter, Ashraf al-Qot, said he expected the battle for Sirte to be harder than that for Tripoli, which fell in just a few days late last month.
"Sirte is not as big as Tripoli symbolically but we think the resistance in Sirte will be greater than that of the capital because Gaddafi's soldiers retreated there," said Qot.
"Mercenaries do not surrender, they will fight till they die, but Gaddafi's former soldiers might surrender because he's not likely to be there to command their loyalty," added the 17-year-old.
Ali Ligod, 25 and also from Misrata, predicted small clashes and a Tripoli-like retreat by Gaddafi's men.
"In Tripoli, we thought there would be a huge fight but there were only a few simple battles," Ligod told AFP.
"We would prefer to settle things peacefully and not spill blood.
"We are not like Gaddafi's forces. We value every soul from our ranks or theirs.
"We have a goal which is freedom; they have nothing."
The task of the forces loyal to Libya's new rulers appeared to have been made easier as their advance was preceded by a series of NATO air strikes in and around Sirte.
In an operational update, NATO said it had on Wednesday struck a command and control node, a military vehicle storage facility, four radar systems and two surface-to-air missile systems in the vicinity of Sirte.