"Your actions reflect the finest tradition of United Nations peacekeeping," the UN Chief wrote in his letters of commendation to the two soldiers.
The commendation comes after Private Chancy Chitete of the MDF was posthumously awarded the "Captain Mbaye Diagne Medal for exceptional courage."
Guterres said during the speech to award Chitete in New York, USA, that eight other peacekeepers had been nominated for the award which "showed the extraordinary courage and commitment of our peacekeepers."
All eight were from Africa, two being Malawians.
On Aidini, the UN Chief said:" As the second-in-command, you showed the utmost professionalism by taking over command and with exceptional leadership and inspired the troops to fight on and to repel the enemy attack.
"Your successful intervention contributed significantly in preventing further loss of life. You demonstrated exceptional bravery beyond the call of duty."
Guterres also saluted Chatsika, who was involved in the same operation in Eastern DRC, saying: "As the medical officer, you showed the utmost professionalism by treating casualties during heavy and sustained enemy fire.
"Your successful intervention contributed significantly in preventing further loss of life. You demonstrated exceptional bravery within the call of duty."
Peacekeepers from Burkina Faso, Chad and South Africa were also nominated for the Diagne Medal and also received letters of commendation from the Secretary General.