Which version of GG is this? Pre-TCW? If not, GG might last 2 seconds. If it is Pre-TCW then he might last 5 seconds
I honestly don't see how Grievous would lose in 2 seconds. When Sidious decided not to use his force powers to take on Savage and Maul he killed them within 4 minutes. That's still a stomp in my opinion but naturally he could have defeated them by speedblitz. He can't speedblitz/use any of his force powers here, just a saber duel.