Worf vs Solo

[Kalmageddon]

Cloaking devices seem to be something beyond the ability of Star Wars sensors to detect, it's tachyon based tech, meaning it's not simply becoming invisibile, as far as I know. I remember one episode of TNG when a cloaking device prototype was modified to actually make the ship go through solid matter, so it's obviously something far more advanced than just some invisibility device.
The ship is basically undetectable for someone who isn't actively scanning for it and even then it seems to require a good amount of scientific knowledge and improvisation to actually spot the cloaked ship. Han may have the latter, but he lacks the former.

So basically, Defiant cloaks, Millennium Falcon can't spot it in time, Defiant locks on to some vital component (engines most likely), opens fire and the Millennium Falcon is done for. You could argue that deflector shields would take the hit, which means that the Millennium Falcon can simply power the hyperdrive and be gone, assuming it's instantaneous. Can't remember if it is. Otherwise, aside from running, I don't think the Millennium Falcon can have a chance against the Defiant. It's still a battleship against what is basically a freighter.

Hand to hand combat obviously also goes to Worf, the guy managed to kill multiple Jem'Hadar in hand to hand combat, which are consistently protrayed as being skilled fighters in every way superior to a humans (except when Sisko misteriously manages to drop them with an elbow strike, but I attribute that to sloppy writing). Worf is better than even their best fighters.

The only contest in which solo could potentially win is in a straight up gun fight. Worf is a good shot, but not an exceptional one, if I remember correctly, while Han solo is obviously a skilled marksman and gunslinger and is used to fighting dirty, so I imagine he could probably get the drop on Worf.