State television said army forces, working with pro- regime militia, had seized control of the town of Rabia after heavy fighting with rebels.
It was the second strategic victory for pro-regime forces in Latakia in less than two weeks, after government troops seized the town of Salma from rebels on January 12.
"In the coming weeks, we will be able to announce that all of Latakia -- city and province -- is free from armed groups," a Syrian army commander in Latakia told AFP.
Rabia had been held by the opposition since 2012 and was controlled by a range of rebel groups including some made up of Syrian Turkmen, as well as Al-Qaeda affiliate Al-Nusra Front.
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State news agency SANA said government forces were "combing the area to dismantle any explosive devices or mines planted by the terrorists".
It said many rebels had been killed in the fighting but provided no other details.
According to the Syrian Observatory for Human Rights, Rabia fell today after a regime advance that left the town surrounded.
He said senior Russian military officials oversaw the battle and that Russian air strikes "played an essential role" in the fight.
With Rabia's capture, government troops are closing in on rebel supply routes through the Turkish border to the north, he added.
Armed opposition factions have used northern parts of Latakia province to carry out rocket and bomb attacks on the provincial capital along the coast.
Backed by Russian air power, pro-regime forces are chipping away at that territory in a bid to secure the Assad clan's heartland.
"By controlling this road, the Syrian army can block rebel movements towards the south, towards Latakia, and the rebels will have a hard time getting close and firing missiles at the (coastal) airport," he added.
Russia's air force has operated out of the Hmeimim military airport in Latakia province since September 30.
The regime's latest advance came as world powers intensify efforts to reach a political solution to Syria's war.