The answer is Grantley Marshall or Daddy G, original member of the Wild Bunch Soundsystem which later became known as Massive Attack.
I'm not sure who the first chaser is - Massive Attack are a band with a revolving cast singers and musicians, the first chaser sings in the clip so I will assume he is a singer of one or more of their songs. Daddy G is chased later by other more recognisable members of the band later on in the flmclip - Robert del Naja, Mushroom and then some extras (presumably friends of the band) join the chase.
Massive Attack are a band out of Bristol which is on Britain's West Coast. The town of Bristol has a vibrant cross cultural music scene heavily influenced by its African slave trade heritage. Bristol is credited for the trip-hop sound.
Massive Attack have great videos, check out their music clips on Youtube. Massive Attack released an excellent DVD compilation a couple of years ago which is now dated with the bands new releases. Here's the official animated filmclip for their new single Splitting the Atom. Watch it in 720HD courtesy of the Futureshorts Channel on Youtube.
I found the official art film music clip for their previous single Paradise Circus (now rare) which was up on youtube for a little while. (Hey - you can link it on facebook).