Video shows a Ukrainian soldier from the Azov Battalion firing the missile at the Russian military vehicle and landing a direct hit, sending a black plume of smoke into the air.
Ukrainian troops have blown up a Russian armoured vehicle with an anti-tank guided missile in the besieged city of Mariupol after the soldiers refused Moscow's ultimatum to lay down their arms.
Video shows a Ukrainian soldier from the Azov Battalion firing the missile at the Russian military vehicle and landing a direct hit, sending a black plume of smoke into the air.
The soldier, whose comrade across the street can be seen holding a grenade launcher, quickly retreats inside a building in Mariupol and can be heard shouting 'yes' after the successful hit.
The Azov Battalion posted the footage after Russia told Ukrainian troops, who have been holed up in the Azovstal steel plant in Mariupol, to lay down their arms within two hours if they wanted to live.
The Russian Defence Ministry called on the troops to withdraw from the steel plant between 1400 and 1600 Moscow time (1100 and 1300 GMT) "without exception, without any weapons and without ammunition".
"All who lay down their arms are guaranteed to remain alive," the Defence Ministry added.
But the Ukrainian troops, who have defended the city for seven weeks, defied Moscow's demands as the video showed their continued resistance.
Kyiv today said Russia's new offensive in Eastern Ukraine will fail because Moscow's forces lack the strength to break through Ukrainian defences.
The Azovstal plant, which covers the territory of about 11 square kilometres (over 4 square miles) is the last major Ukrainian pocket of resistance in Mariupol, a strategic port city on the Sea of Azov.
Mariupol, which has been encircled by Russian troops for weeks, has seen the fiercest fighting and most comprehensive destruction since Russia sent troops into Ukraine on February 24.
The defiant move by Ukrainian troops comes after Russia claimed it had hit more than 1,200 Ukrainian targets with missiles, airstrikes and artillery as Vladimir Putin's troops launched their new offensive in the Donbas region in Eastern Ukraine, a report by Daily Mail said.