A fast field, a match race and a new Masters record highlighted the day.
Jordan Chipangama won the race in 63 minutes.
Kastor now has every Masters record from 5K to the half marathon.
The Olympic silver medalist will try to break the American Masters half-marathon record.
The 40-year-old has had great success in San Jose.
Lynne Hurrell sets a new age group national record of 2:21:20.
Seven runners qualified for the U.S. Olympic Marathon Trials in San Jose on Sunday.
Elite runners will try to qualify for the 2016 U.S. Olympic Marathon Trials.
The three-time Super Bowl champion will take the Remix Challenge this weekend at Rock ‘n’ Roll San Jose.