A ministry statement said three Turkish soldiers were lightly wounded when 35 mortar rounds were fired at the observation point in what it described as a deliberate attack.
"If the regime continues its attacks we will take the necessary action. No one should have any doubts about that," Turkish Foreign Minister Mevlut Cavusoglu said during a joint press conference in Ankara with his French counterpart, Jean-Yves Le Drian.
Thursday's attack, which also damaged equipment and facilities at the observation post, came amid a ground offensive launched by Syrian government forces in late April against rebel-held areas near the Turkish border. Al-Qaida linked militants and other jihadi groups have come to dominate the Idlib enclave, which first fell under rebel control in 2015.
The Russian Defense Ministry said Turkey had asked Russia for help after one of its checkpoints in the de-escalation zone came under fire from shelling. In response to that request, Russia launched an airstrike that destroyed a group of rebels and the weapons used in the attack.
The ministry said Turkey gave Russia the coordinates for the militant's location for the strike.
Syrian opposition activists reported shelling and airstrikes on different rebel-held parts of Idlib and the central province of Hama. The opposition's Britain-based Syrian Observatory for Human Rights said four people were killed in the town of Khan Sheikoun alone on Thursday.
The recent government offensive began after a Russia-Turkey-backed truce in place for months failed to reduce the influence of extremists in the stronghold. The Russian-Turkish agreement established demilitarized zones with observation posts to monitor the cease-fire.
Speaking to reporters, Cavusoglu denied news reports that Turkey and Russia had reached a new cease-fire agreement for Idlib but said the two countries were engaged in "serious and sincere" efforts to stop the conflict.
Le Drian said: "(Idlib) is such a dangerous and explosive zone that it is important that the cease-fire is meticulously respected."