Jarasandh was the father-in-law of Kansa. When he learnt about Kansa’ death he surrounded Mathura with a huge army. Sri Krishna was well aware of Jarasandh’s might and bravery. He was also convinced that it would not be easy to defeat Jarasandh. So, he remembered Daruk–his eternal charioteer and sought his help. Daruk appeared with a divine chariot named Sugriva– pushpak. The chariot was well armed with all the divine weapons of lord Vishnu.
Sri Krishna and Balarama then entered the battlefied mounted on that divine chariot. A fierce battle was fought between Sri Krishna and Jarasandh’s army. Jarasandh covered Krishna chariot with his various weapons but Sri Krishna destroyed them with his ‘Chakra’. Sri Krishna then destroyed Jarasandh’s army by showering volley of arrows from his famous bow–Sharang. Seeing the death and destruction in his army, Jarasandh came forward to fight Balarama.
Balarama attacked Jarasandh with his dangerous weapon–Hala (plough) and destroyed his chariot. Jarasandh fell down on the ground and as Balarama was about to kill him Sri Krishna requested Balarama not to kill Jarasandh. After being defeated, Jarasandh sought the help of Kalyan, who had a large army. Kalyavan agreed to help Jarasandh and surrounded Mathura with his army.
Realizing that Mathura was no longer a safe place to live, Sri Krishna shifted the whole population of Mathura to Dwarka and went to fight Kalyavan. The battle continued for a long period and after realizing that it was not easy to defeat his enemy, Sri Krishna, ran towards the cave where ‘Muchkund’ had been sleeping since many past eras. Muchkund was blessed with a boon according to which any person upon whom he put his glance after waking from his sleep would die. Krishna hid himself behind Muchkund. Kalyavan, who was chasing Krishna, entered the cave and kicked Muchkund. Muchkund opened his eyes and saw Kalyavan. Kalyavan was burnt to ashes. This way, Sri Krishna was able to defeat his powerful enemy by his cleverness.