Attacks by Colonel Muammar Gaddafi's fighter jets and artillery have been repulsed by the rebels threatening to end his 41-year rule of Libya.
While the dictator sounded a defiant note during a public appearance in Tripoli, a surprise assault by his forces using 122mm heavy artillery on the town of Brega was repelled after bloody fighting in the town.
And air strikes on an arms dump outside Ajdabiya again failed to ignite the enormous weapons stockpiles hidden in bunkers filmed by Sky News earlier in the week.
Eyewitnesses say the battle in Brega was waged across sand dunes on the edge of town and around its university.
Col Gaddafi's air force again struck by dropping bombs on the university, but failed to stem the rebel counter-attack.
While their forces have managed to hold off pro-Gaddafi onslaughts so far, opposition leaders continue to plead for outside airstrikes to help them oust the ruler.
The US has backed away from the option, with Secretary of State Hillary Clinton saying military assets could be used to support the movement of supplies to Libyan areas in need, but a no-fly zone was not an immediate priority.
However, the Cairo-based Arab League - which has suspended Libya - has said it could impose a no-fly zone in co-ordination with the African Union if fighting continued.
Sky News filmed a large number of SUVs, trucks and pickups, all with large weapons in the back, bristling with well-armed militia heading towards Brega.
The question is now whether or not the rebels can turn their counterattack into a more sustained offensive and move the pro-Gaddafi lines further west after days of stalemate between them and the regime.
The attack on Brega, a strategic oil facility 460 miles of the capital of Tripoli, illustrated the deep difficulties experienced by the Libyan leader's armed forces.
An array of militiamen, mercenaries and military units, they have failed to halt the uprising that has swept over the entire eastern half of Libya since February 15.
The rebellion and subsequent crackdown by Col Gaddafi's forces have sent a huge wave of refugees towards the country's borders, with the UN estimating some 180,000 people have been displaced.
Egypt and a handful of European nations, including Britain, have launched emergency airlifts and sent ships to help them flee the country.
Actress Angelina Jolie, a UN goodwill ambassador for refugees, appealed for all nations to give people safe passage, evacuation if needed, and ensure they have asylum.
"All I'm asking is that civilians be protected, and not targeted or harmed," she said.
"We don't want to look back and find their deaths are on our hands."