Game SummaryWith their championship title to defend, the Colts began the season in the annual Thursday night kickoff game against the visiting New Orleans Saints.  In the first quarter, Indianapolis began their year with Super Bowl MVP QB Peyton Manning completing a 27-yard TD pass to WR Marvin Harrison for the only score of the period.  In the second quarter, the Saints would get their only touchdown of the game with former Colts DB Jason David returning a fumble 55&#160;yards, while kicker Olindo Mare would get a 34-yard field goal.  Indianapolis ended the first half with kicker Adam Vinatieri kicking a 33-yard field goal.  In the second half, the Colts took control for the rest of the game.  During the third quarter, RB Joseph Addai got a 2-yard TD run, while Manning hooked up with WR Reggie Wayne on a 28-yard touchdown pass.  In the fourth quarter, Indianapolis sealed the victory with Vinatieri getting a 33-yard field goal, Manning & Wayne hooking up with each other again on a 45-yard TD pass, and DB Matt Giordano returning an interception 83&#160;yards for a touchdown.
Question: Who threw the only touchdown of the first quarter?
Answer: Peyton Manning