Krishna knows that their men are not enough to fight with Jarasandh. Hence, He is the most wanted man with Balram, hence, Krishna, to save Mathura and it's men, decide to surrender and avoid the war.
Krishna gets his chariot and weapons and makes Balram leader and starts for fight.
Ramanand Sagar presents it beautifully in the serial Krishna.
Channel Saurabh Parikh