In the second 450 heat, it was Justin Hill who lead the field through the first turn on his Smart Top Honda and lead the opening lap from Monster Energy Yamaha's Aaron Plessinger and Red Bull KTM's Cooper Webb.
The first lap did not work out so well for both Rockstar Husqvarna's Jason Anderson and Monster Energy Kawasaki's Adam Ciaciarulo with both riders suffering crashes, leaving them buried at the back of the field.
Back up front Webb passed Plessinger just before the halfway mark but trailed Hill by just under 4 seconds. Round one winner, Justin Barcia aboard his Monster Energy Yamaha. also worked his way forward moving from 5th to 3rd passing both Factory Honda's Justin Brayton and Plessinger, with Brayton also making his way past Plessinger
Cianciarulo moved his way back into a qualifying position with just over two minutes to go, with Anderson doing likewise shortly after.
HIll held on to win by two seconds ahead of a fast-finishing Webb, with Brayton crossing the line in third after Barcia's bike expired on the final lap, forcing him to the LCQ
It was privateer Joan Cross who captured the holeshot in the 450 LCQ, with both Barcia and Wilson rounding the first turn outside the top five.
Barcia made quick work of the riders in front of him, quickly moving to the lead and going on to take a comfortable win ahead of Wilson who took a little more time to work his way into a qualifying position.
Cade Autenrieth moved his way into third and a safe qualifying position, while behind him, Jason Clearmont had his hands full with Alex Ray as the two riders started the final lap.
Despite his best efforts, Clearmont could not hold off the hard-charging Ray who came all the way back from 10th position early in the race to seal the final spot in the nights' main event.
Australia's Joel Wightman finished down in 9th position, and while it was his best performance to date, it put an end to his night in Oakland.
When the gates dropped for the nights 450 main event, it was once again Roczen who lead the field through the first turn with Cianciarulo and Tomac on his rear wheel.
Tomac quickly made the pass on his team-mate for second position, but Cianciarulo promptly responded, making a move Straight back while behind them Webb moved into 4th.
Webb put some pressure on Toamc for third, but a small mistake took the pressure back of Tomac.
With 12 minutes left to run, Tomac forced the issue with Cianciarulo, putting in a little bump and run move to take over second position.
Anderson, who started just inside the top ten, worked his way into 5th position by the halfway mark of the race. Still, the real action was about to head up out front, and with nine minutes left to run, Tomac made his move for the lead making a clean pass on Roczen as the two riders approached lappers for the first time.
Barcia was another rider on the move, coming from the LCQ, his start in the main left him well outside the top ten, but worked hard to move into 6th as the race wound down.
Back up front, Tomac made a mistake in the sand section, losing control and running off the track, allowing Roczen to re-take the lead.
The lead was short-lived by Roczen, with Tomac re-passing Roczen after the triple for the second time in the race, while at the same time, Webb moved by Cianciarulo for third and set after Roczen in second.
At the line Tomac took the win, with Webb putting a last turn pass on Roczen for second position, with the two riders making contact, leaving Roczen to limp off his bike with what looked to be a leg injury in third.
Cianciarulo held on to finish 4th with Anderon in 5th and Barcia in 6th
Dean Wilson held worked his way through the field to finish 7th ahead of HIll in 8th, Baggett in 9th with Malcolm Stewart rounding out the top ten.
In the championship standings, Roczen continues to hold down the points lead by a narrow three points from Tomac, with Barcia 12 points further back in 3rd. Anderson holds down 4th just two points behind Barcia, with Webb one point further back in 5th after tonight's second-place finish.