Both because it was DLH's second last fight, and against a talented smaller guy. DLH won enough rounds from PBF-- even if you only give him 3-5 rounds-- to prove he can hang with a slower, less talented puncher in Pac. All DLH has to do is win 6-7 rounds with a couple close rounds and he gets a UD. Wait and see.
That fight has absolutely zero relevance to this one. Mayweather had been campaigning as a welterweight for some time before he fought DLH at one weight division north of that. Pacquiao is effectively jumping 2 weight divisions, he has never fought higher than lightweight, and has only fought in that division once. He is a super-featherweight fighting a light-middleweight (Oscar hasn't fought at 147 since 2001). Plus, Mayweather and Pacquiao have completely different, opposing styles. DLH will win by stoppage, but it has no connection/relevance whatsoever to his fight with PBF.
PBF is a tiny welterweight, and can STILL make 140 lbs easily. Yes, different styles...I am comparing size and DLH's ability to close the talent gap.
I think its gonna be a competitive fight. People keep bring up that DLH is a light middle. If he makes 147 he is a welter who has being fighting at higher wieghts also. Obviously its a bigger jump for Manny who i think can give DLH a very tough fight by being on his toes and bouncing in and out of range. Im looking forward to it. Ideally for me, i would like a split decision victory for the very battered and retiring old man. Manny even in defeat would have gained a lot of respect for taking on the challenge, and will move down to Lightwelter and have another superfight against Ricky Hatton. Who will also retire afterwards.