St - Pierre won his past 12 fights , with seven of his last eight going 25 minutes .
GSP walked away from the sport in 2013 , citing his wear and tear from competing at such a high level for so long .
GSP     won GSP 's past 12 fights , with seven of his last eight going 25 minutes .
GSP walked away from the sport in 2013 , citing his wear and tear from competing at such a high level for so long .