Which battle in 1221 ended with Jalal ad-Din fleeing across the Indus River?

The battle in 1221 that ended with Jalal ad-Din fleeing across the Indus River was the Battle of the Indus.

The battle was fought on 24 November 1221 between Genghis Khan’s Mongol army and the forces of Jalal al-Din Mangburni, the last major ruler of the Khwarazmian Empire. Jalal al-Din had regrouped after defeating a Mongol force at the Battle of Parwan, but a dispute over plunder caused many of his Afghan allies to leave.

Pursued by Genghis Khan, Jalal al-Din retreated toward the Indus. His army made a strong defensive stand on the riverbank, but the Mongols eventually overwhelmed it. With defeat unavoidable, Jalal al-Din reportedly mounted his horse and leapt into the river, escaping into India while much of his army was destroyed or captured.

The Battle of Parwan was the earlier victory that encouraged Jalal al-Din, not the battle at which he fled. Yehuling belonged to the Mongol war against the Jin dynasty, and the Kalka River battle occurred in 1223 against forces in the western steppe.