Jock led virtually the entire race at Hayward Field, holding off UCLA's Cory Primm (1:46.36) at the finish.
The top three finishers in each of Friday's three heats, plus the next three-fastest times overall, earned berths in the semifinals of the NCAA Championships June 8 at Drake Stadium in Des Moines, Iowa. The 800 final is scheduled for June 10.
Jock competes in the NCAA West 4x400 relay quarterfinals Saturday along with teammates Napoleon Greene, Chris Carson and Dominic Jester at 4:45 p.m. in Eugene.
UCI senior Matt Lahti did not advance in the hammer throw Friday with a mark of 173 feet, 6 inches.
Senior Madeline LeDuc also did not move on with a mark of 39-7 3/4 in the women's triple jump.