Tough to say, but Frankie Gomez (8-0) definitely looks like he has the tools to win one of the major four titles.
Benavidez Jr would be another one, but he already has 10 fights, so he doesn't match your criteria. ;)
DeGale is 9-0 and is rumoured to be getting a title shot for his 10th fight so he might not have to wait long (even if it is for a bull**** version on the WBA SMW title)