(Tampa, FL)  --  Former Oregon quarterback Marcus Mariota showed why he was a first round pick in his regular season debut yesterday.  The 2014 Heisman winner finished 13-of-16 for 209 yards and four first-half touchdowns to lead the Titans to a 42-14 win over the Buccaneers.  Mariota became just the second rookie to post a perfect passer rating, joining only Robert Griffin the Third.