From wikipedia!
Fitzpatrick played his first NFL game on November 27, 2005. Coming into the game in the second quarter against the Houston Texans to replace an injured Jamie Martin, Fitzpatrick lead the Rams from a 24-3 halftime deficit to a 33-27 overtime win, throwing for 310 yards and three touchdowns. This made Fitzpatrick one of only five players who passed for 300 yards in their NFL debut. The others were Otto Graham, 346 yards (1950); Ed Rubbert, 334 (a replacement player for the Washington Redskins during the 1987 strike); Mark Rypien, 303 (1988), and Peyton Manning, 302 (1998).