Rupp swung wide early and made a strong move. Anyone who's been watching rupp this year would know he has no tactical awareness. He has always had the speed, but always seems to make newbie mistakes during the race to foil his chances later.
As to why he is an idiot at rationing his energy when his teammate is a master at it is beyond me. The margin of error is very little at this level and one needs to be smart about race surges.