Still searching for their first win of the season, the Bengals went home for a Week 7 AFC North duel with the Pittsburgh Steelers.  With Carson Palmer still out with a sore elbow, QB Ryan Fitzpatrick was given the start. In the first quarter, Cincinnati trailed early as Steelers QB Ben Roethlisberger completed a 2-yard TD pass to RB Mewelde Moore, along with kicker Jeff Reed getting a 21-yard field goal.  In the second quarter, the Bengals answered with Fitzpatrick completing a 5-yard TD pass to WR Chad Ocho Cinco.  In the third quarter, Pittsburgh responded with Moore getting a 13-yard TD run.  Cincinnati would respond with kicker Dave Rayner nailing a 26-yard field goal.  However, in the fourth quarter, the Steelers pulled away with Roethlisberger completing a 50-yard TD pass to WR Nate Washington, Moore getting a 2-yard TD run, and QB Byron Leftwich completing a 16-yard TD pass to WR Hines Ward.  Earlier in the game, Ward destroyed Bengals linebacker Keith Rivers with a vicious legal hit, breaking Rivers' jaw. With the loss, Cincinnati dropped to 0-7.  The team's first such start since 2002.

Based on the above article, answer a question. Who threw the longest touchdown pass of the game?
Roethlisberger