He couldn't punk him with the force. After gaining a sith amulet, Ulic Quel-Droma was literally rippling with darkside energy. He was able to hurl back both Nomi Sunrider and Cay Quel-Droma about 50 feet purely by shouting. They're pretty close in the force actually, Vader's done more, but nothing that can be considered much better than what Ulic has done, let alone better at all.
Yes, Ulic wins - he kileld Warb Null in one move, pwnd Mandalore when they were using weapons, even though he had no mount and Mandalore did, and Ulic started on unsolid ground, he resisted the mental powers of Freedon Nadd and Kind Ommin at the same time and then killed Ommin, he stalemated Kun in a saber duel, and, when cut off from the Force, held off a relatively strong Dark Jedi even though he wasn't trying to hurt the Dark Jedi but only defend himself.
Vader? If strong, but not quite strong enough to beat Ulic.
Zomg ulic > vader because he killed mandalore, Vader could crush a military tank with ease and sent animals and thugs flying more than 50 feet breaking every bone in their body when they hit something, Vader even levitated with the force in empire betrayel.
Rotj sidious will pwn ulic and vader is 80% of that sidious who is alot stronger than his former ROTS self who already would > ulic