To motivate your team, you decided to reward a team member who performed well. This hurt cohesion in the team. what to do?

Try always to implement a win-win reward, like you can reward a team who has a good performer, not only the performer

there should a clear direction, procedure or QMS in place and will be strictly followed. HR policies defines these procedures as part of it, and rewarding system is indicated too. Thus, it will be clear to every employees that there is an existing policy about it. 

There is no exceptions in this , a clear well stated bonus / penality system should be established, only the one who worked hard deserves to get rewarded , no compliments. Black sheeps of the team will always wait for free rewards in the contrary.