In Virat war all Kuru warriors including Bhisma Drona and Karna were vanquished by Arjuna.
Now, the same Arjuna in Kurukshetra war even with Lord Krishna with him, could not face these warriors. Arjuna killed each and every Kuru warrior through deceit.
Shalya Badha Parva 60
Lord Krishna also accepted that Karna, Bhishma and Drona could not be vanquished by Pandavas in a fair combat. Then how Arjuna defeated all of them in Virata war?