Not going by a set definition of "dark horse" or any requirements or anything: Edgar Sosa, flyweight Tepparith Singwancha, junior bantamweight Mario Rodriguez, strawweight Hassan Ndam, middleweight Troy Ross and Firat Arslan, cruiserweights
in title fight defeats these guys fought some real hard and dignified fights I thought Arslan won vs Huck too after the majority on ESB saw the fight as a joke going in
Sergey Kovalev, I don't see anyone beating him right now. He's the anti-slick, may even look crude or robotic to some, but he's damn very effective. Almost as menacing as GGG just a bigger version. From Russia with love another terminator from the eastern bloc. The Klits, GGG, and soon Kovalev will be another powerhouse in boxing. What they feeding these guys?
Yup. Most seem to think both Ross and Arslan won their last fights against the two best CW's in the world. Ndam's loss to Quillin was a solid outing. Despite being dropped 6 times, I had him only losing by 2 points, if memory serves. Mario Rodriguez lost his belt he won from Joyi last time out too. I unfortunately haven't watched it yet but I heard he beat Katsunari Takayama and got robbed.
Carl Frampton. Comfortably outpointed Raul Hirales, who has rebounded and is now going places, beat the living beejayzus out of a (admittedly past prime) Steve Molitor, then became the first man to stop an underrated (and at 27 and undefeated in 3.5 years definitely NOT shot as some were suggesting!) Kiko Martinez. His day will come (ok, maybe slightly inappropriate to use an IRA slogan on a Protestant man whose missus is Catholic and whose team did much to try to counter sectarianism!)
just saw a very impressive jr welter, Terrance Crawford, near shut-out Bredis Prescott on the undercard of a TV fight. Crawford's only had a few pro fights (winning all,most by KO), but fights as cool as a veteran, can crack 'n has every tool.