When the Boss and the Great Master face off, the Boss is definitely not a match for the Great Master. Each has their own expertise, right? As for why it ended in a draw, everyone can use their imagination. Serious reasons could be things like equipment or class suppression, while more fantastical reasons might be—inside the Great Master's mind: "It's already dark, who wants to keep fighting a man on the computer? Better to end it in a draw and log off to spend time with my wife!"... Actually, achieving a draw is harder than winning a match!
Of course, it could also be that the Boss is a prodigy. If Victor Feng could team up with the Great Master and Vivian to run a dungeon, as for Susan... maybe she could watch? Be a bystander? Cheerleader?