The Ravens lost their second straight game in a contest with the Carolina Panthers. The Panthers got on the board first with a 21-yard field goal by kicker John Kasay. Ravens quarterback Steve McNair was knocked out in the first quarter with a concussion, and backup Kyle Boller took over, connecting on a touchdown pass with Mark Clayton, on a pass intended for Derrick Mason that was tipped to Clayton. The Panthers responded when Drew Carter caught a 42-yard touchdown pass from Jake Delhomme, and Kasay kicked another field goal, this time from 31 yards. The Panthers went into halftime with a 13-7 lead. The third quarter was scoreless, and midway through the fourth quarter, Panthers kicker Kasay kicked his third field goal of the day from 21 yards out. Ravens wide receiver Clayton caught his second touchdown pass from Boller, again on a tipped pass, bringing the score to 16-14 Carolina. Panthers quarterback Delhomme continued his career day, this time throwing a 72-yard touchdown pass to wide receiver Steve Smith. Delhomme threw for a career-high 365 yards. Ravens tight end Todd Heap caught a 7-yard pass from Boller in the final minutes, but it wasn't enough as the Panthers extended their current winning streak to four games. The loss dropped the Ravens to 4-2, and 1-1 against NFC Opponents.

Answer this question based on the article: How many touchdown receptions did Mark Clayton have?
2