Bol came from back in the pack and exploded through the middle of the other riders to take a big win ahead of Peter Sagan (BORA-hansgrohe) and Jasper Philipsen (UAE Team Emirates).
It's the first WorldTour win of the 23-year-old's career, with the Dutchman building upon his Nokere Koerse win earlier in the season with his showing against the quality field of sprinters present in California.
The stage was far from a procession for race leader Pogačar whose lead was under constant threat during the race.
Maximilian Schachman (BORA-hansgrohe) was once again on the attack after his bold move on the early slopes of Mt Baldy the previous stage. The German was part of the early breakaway, forcing UAE Team Emirates to keep the race close as Schachmann was only a minute and 25 seconds behind Pogačar at the start of the day.
When it looked like Schachmann was mostly under control, EF Education First led a brutal surge up the toughest climb of the stage, dropping most of the peloton and all of Pogačar's teammates.
Numerous attacks by George Bennett (Jumbo-Visma) were nullified largely by EF Education First, and ended up in the initial breakaway being caught.
Schachmann attacked again with Davide Ballerini (Astana) and Lennard Hofstede (Jumbo-Visma), before the Deceuninck-QuickStep duo of Remi Cavagna and 3rd-placed overall Kasper Asgreen bridged across.
With Asgreen only 17 seconds down on Pogačar's lead, there were nervous moments until UAE Team Emirates grouped at the front of the main bunch to bring Asgreen back into the fold with under 10 kilometres to go.
"It was a really tough stage once again," said Pogačar. "On the climb, EF (Education First) was really making the pace, it got most of my riders dropped, lucky we had one rider in the breakaway."
"After the attack of Asgreen, I knew my team was coming from behind with full gas. I was a bit nervous, but I know my team is good and I count on them. They brought Asgreen back and I was good."
