Winning the first 3 battles per day automatically triggers the Daily PVP Reward, which is randomly predetermined from 9 options. Players can have option to respin by paying 5 Gold to get another chance to "Open Another" and select another Reward.
The Daily PVP Reward resets daily.
With Patch 1.3.0, the Daily PVP Reward was updated to include the new Power Cells.
With PVP Tournament 03: Miles Morales, the Daily PVP Reward was changed and including now PVP exclusive Iso-8 Crystals.