Bushell got ahead of Coates, who started from pole position, into the first bend and then quickly drew clear of the squabbling pack behind.
Eventually though Coates was able to break clear in second place and six fastest laps in a row brilliantly saw him bring the gap to Bushell from over two seconds down to just four tenths of a second starting the final lap.
Team Pyro’s Bushell however was not to be denied and used all his experience to cling on and take the win by just 0.258s ahead of Ciceley driver Coates.
It is Bushell’s fourth win in a row and his seventh out of the 12 races so far in 2017. He now holds a massive 98-point lead over second-placed Paul Rivett in the championship which means that, in theory, he could clinch the title as early as the next two rounds at Rockingham at the end of August.
CLICK HERE for the points table.
Rivett finished the race in third place but on the podium could have been his WDE team-mate Lee Pattison – Bushell’s chief title rival going into the encounter but who retired while lying second when his car cruelly slowed.
Bushell reflected: “I got a great start and the car felt mega in the opening laps which helped me build my lead but then the handling started to deteriorate and Max was suddenly getting bigger in my mirrors. Luckily I kept it together on that final lap and the result is fantastic for my championship.”
Coates commented: “When Lee stopped I was suddenly into second and so gave it everything – we’ve had great pace here this weekend and I was really going for the win. I’m sure with one more lap I’d have had Mike.”
Rivett said: “That was very cruel luck on Lee’s part but WDE have at least kept Pyro honest at the top of the teams’ championship. As for the drivers’ title… Mike is obviously driving really well but I don’t think you can say it’s over while it’s still possible. It’s just that more unlikely, that’s all…”
Rivett’s third place in the race came thanks to a bold move that took him past Westbourne’s James Dorlin who later found himself shuffled back to an eventual sixth by both DRM’s Daniel Rowbottom and WDE’s Dan Zelos.
Sam Randon (Westbourne), James Colburn (PP/Westbourne), Pyro’s Nathan Harrison and JamSport’s Aaron Thompson completed the top ten. Pyro’s Jack McCarthy was 11th after running off track briefly, just ahead of team-mate Lucas Orrock who recovered strongly to finish 12th following an opening lap off caused by contact in a close-knit lead battle.
His recovery involved getting the better of Ciceley pair Sam Osborne and Jade Edwards and WDE’s Nicolas Hamilton – for a while this trio put on a great show before eventually ending up in 13th, 14th and 15th positions. JamSport’s Jamie Going completed the runners in 16th after a losing time with an opening lap incident
In addition to Pattison, Ciceley’s Luke Reade and STR’s Shawn Taylor were also retirements.