Tanaji is famously known for the Battle of Sinhagad in 1670. At Shivaji's request, he pledged to recapture the fortress of Kondana near Pune. According to many accounts, he received the summons while at his son's wedding, and immediately left the festivities. Tanaji and his troops scaled the fort with the help of domesticated monitor lizards (ghorpad in Marathi), to whom they tied ropes and sent crawling up to the top of the ramparts. (The ghorpad grows up to 1.8m in length, and its natural habitat is rocky terrain, which it scales by gripping crevices with its strong claws). Tanaji's pet ghorpad successfully climbed the ramparts after two failed attempts. Tanaji and his men than climbed the fort in pitch darkness. He and his men recaptured the fort from Udaybhan Rathod, fortkeeper of Jai Singh I.
A fierce combat took place between Tanaji and Udaybhan. Udaybhan managed to rid Tanaji of his shield, but Tanaji fought on by tying a cloth over one of his hands and using it to ward off Uday Bhan's sword attacks. Despite a lengthy fight, Tanaji was killed in battle, and Shivaji renamed the fort from Kondana to Sinhagad in his honor. Per legend, Shivaji's words after hearing about the demise of Tanaji were Gad ala pan Sinha gela("although the fort was captured a lion was lost").
Tanaji continues to be a popular figure in Maratha culture. A povada (ballad) is written after him, and there is a Marathi novel named Gad Ala pan Sinh Gela based on his life, as well as a film.