Trying to snap a three-game losing skid, the Cardinals went home for a Week 10 duel with the Detroit Lions.  In the first quarter, Arizona trailed early as Lions RB Kevin Jones got a 4-yard TD run.  The Cards would reply with kicker Neil Rackers nailing a 23-yard field goal.  In the second quarter, the Cardinals took the lead with QB Kurt Warner completing a 1-yard TD pass to WR Larry Fitzgerald, while back-up QB Tim Rattay completed a 2-yard TD pass to TE Leonard Pope. In the third quarter, Arizona continued its scorching as Warner completed a 16-yard TD pass to Pope.  Detroit would respond with Kitna completing a 7-yard TD pass to WR Roy Williams.  In the fourth quarter, the Cards pulled away with Warner and Fitzgerald hooking up with each other again on a 20-yard TD pass.  The Lions' last score would be another 7-yard TD pass from Kitna to Williams.
Question: How many yards was the longest touchdown pass?
Answer: 20