I don't like Cain, but I definitely give him credit for that tactic. I believe he threw takedown after takedown on purpose to allow himself to throw the big overhand right.
That's exactly what it was. He got JDS worried about the takedown and sucked him into defending it and playing his game. Cain put the fear of wrestling into him so that JDS never had time to setup his striking game, he took the initiative from the very start and put the pedal to the metal so that JDS was playing catchup for the rest of the fight.
I'd say the most brilliant part of the fight was the way Cain kept crowding in on JDS to take away his space and trap him on the fence and either clinch him for a takedown or dirty box the crap out of him. Usually both. Besides wearing out JDS with the clinchwork on the fence and getting some good punches in, it also prevents JDS from putting any power on his punches since his feet are level and flat against the fence. All you can do from there is arm punch, and that's not going to hurt Cain. It's the same way Randy Couture sucked the life out of many of his opponents.
What JDS should've done but didn't was make Cain pay for those takedown attempts after stuffing the first couple tries. Time him with a good knee to the head every time he shoots in, try and get him with some uppercuts, and once Cain eats enough knees to the head he'll start thinking twice about takedown attempts. From there, JDS can start imposing his striking game, open up the distance and force Cain to play catchup. There were also several times when JDS had a full clinch locked around Cain's neck, and every time he ended up letting it go instead of blasting some knees into the body & head. Missed opportunities.
It was a great fight by Cain, he made the adjustments that needed to be made and beat the hell out of JDS. Now JDS gets to go back to the drawing board and figure out what he needs to do. If he makes the right adjustments, it'll be the best HW fight ever when they meet again.