Despite missing a full season, Cromartie had an excellent pro day showing, and rode that to being drafted 19th overall in the 2006 NFL draft by the San Diego Chargers.
After limited action in 2006, Antonio started half of the games at cornerback for the Chargers in 2007. That year, he was credited with the longest play in NFL history, returning a missed field goal by Ryan Longwell 109 yards for a TD. He picked off a team record 10 passes that year, and 2 more in the post season. He was one of three cornerbacks elected to the Pro Bowl in 2007, and picked off two passes in the game.
His performance tailed off the next two seasons, as Cromartie only intercepted 5 passes over those two seasons. The Chargers began to question his effort, especially the playoff game against the Jets. Ironically, a play against the Jets, played a big role in Cromartie coming to the Jets. Remember this play, where Shonn Greene blew past him for the TD? Watch and smile: