A mixed martial arts event held by Strikeforce, the event took place on April 9, 2011, at the Valley View Casino Center in San Diego, California. Main card: Welterweight Championship bout: Nick Diaz(c) vs Paul Daley, Lightweight Championship bout: Gilbert Melendez(c) vs Tatsuya Kawajiri, Light Heavyweight bout: Gegard Mousasi vs Keith Jardine, Lightweight bout: Shinya Aoki vs Lyle Beerbohm.