Training camp report: Monday, the good – the defense

SANTA CLARA – The 49ers’ run defense is the best in the NFL, but their pass defense stood out on Monday.

Justin Smith dominated the first half of practice, sacking Alex Smith twice. He constantly forced quarterbacks to abandon the pocket and throw on the run. He sat out the second half of practice and as a result the offense played much better.

Perrish Cox picked off Alex Smith. On third and long, Smith threw an intermediate pass intended for Ted Ginn Jr. on the sideline, but Cox broke on the pass before Ginn even saw it.

Chris Culliver intercepted another Josh Johnson pass today. It was third-and-7 and Johnson tried to force a throw to Brett Swain, who had zero separation from Culliver.

Tramaine Brock, playing nickelback, picked off Colin Kaepernick when the second-year quarterback tried to rifle a short pass to Konrad Reuland over the middle of the field. Brock popped the ball out of Reuland’s hands and snatched the ball out of the air. All of the Niners’ cornerbacks played very well.

Michael Crabtree returned to practice Monday as a limited participant. He did all the individual drills, but he watched the team drills from the sideline. After practice he walked off the field with Alex Smith, talking and laughing about something. Smith had his arm over Crabtree’s shoulders.