Despite running the medium ‘prime’ tyre, Sutton’s Motorbase Performance Ford Focus ST cruised away from the soft-shod West Surrey Racing BMW 330e M Sports of Colin Turkington and Hill in the opening stages.
But once Hill got through to second place, the gap was slashed and Sutton had to defend every corner perfectly in the final couple of miles to take the victory.
While Sutton made a good start, front-row partner Tom Ingram was slow away in his Excelr8 Motorsport Hyundai i30 N, and was then shuffled wide at the Wilson hairpin to drop to sixth.
Sutton led by 2.264 seconds at the end of the opening lap from Turkington, and built that to beyond 3s after three laps.
Turkington began trimming the gap, but in turn had Hill and Ingram – now back up to fourth – gaining on him by the halfway point of the race.
Turkington had to defend for a while, allowing Sutton to build his margin once more, before the race appeared to stabilise once again.
Then Hill homed in on Turkington once more, and on the ninth lap of 12 he drew alongside the four-time champion on the back straight.
Hill had two wheels forced onto the grass as they ran side by side, but kept his foot in and swept around the outside of the sister BMW into the esses to wrest second position.
With three laps to go, Hill was 2.416s adrift of Sutton, but he smashed the gap – setting a purple sector one as late as the penultimate lap – and by halfway round the final tour he was in Sutton’s slipstream, finishing just 0.270s adrift.
“We had to pounce at the start,” said Sutton. “We know how long it takes rear-wheel-drive cars to get their tyres up to temperature, especially on the softs they have to be cautious.
“So I had to drive the first three laps as a qualifying session and that’s where I got the gap.
“But one more lap, and maybe Jakey boy would’ve got me.”
Ingram, who has been unwell this weekend, was also on the softs and claimed fourth behind Turkington.
Some way adrift, Adam Morgan and Stephen Jelley made it four soft-Goodyear-shod WSR BMWs in the top six, with Jelley latching onto his team-mate’s bumper as they crossed the line.
This duo moved up a spot when the luckless Ricky Collard pulled his Speedworks Motorsport Toyota Corolla off the track out of fifth place on lap five with an apparent technical problem.
Dan Rowbottom was the leading hard-tyred runner and took a distant seventh in his Motorbase Ford, while Josh Cook, also on the hards, was a lonely eighth at the wheel of the lead BTC Racing Honda Civic Type R.
From the back of the grid, Dan Cammish – on hard rubber – got into the top 10 before he came up against a doughty Rory Butcher.
The Speedworks Toyota driver’s defence stymied the progress of Cammish, who eventually even lost 10th spot to the Power Maxed Racing Vauxhall Astra of Aron Taylor-Smith, and has conceded the championship lead to team-mate Sutton.
BTCC Snetterton - Race 1 results (12 laps)
| Cla | Driver | Car / Engine | Gap |
| 1 | Ash Sutton | Ford | |
| 2 | Jake Hill | BMW | 0.270 |
| 3 | Colin Turkington | BMW | 3.553 |
| 4 | Tom Ingram | Hyundai | 4.541 |
| 5 | Adam Morgan | BMW | 12.961 |
| 6 | Stephen Jelley | BMW | 13.177 |
| 7 | Dan Rowbottom | Ford | 24.648 |
| 8 | Josh Cook | Honda | 29.285 |
| 9 | Rory Butcher | Toyota | 32.283 |
| 10 | Árón T.-Smith | Vauxhall/TOCA | 32.562 |
| 11 | Dan Cammish | Ford | 33.619 |
| 12 | Ronan Pearson | Hyundai | 34.895 |
| 13 | Sam Osborne | Ford | 34.897 |
| 14 | George Gamble | Toyota | 40.414 |
| 15 | Dan Lloyd | Cupra/TOCA | 42.828 |
| 16 | Bobby Thompson | Cupra/TOCA | 42.950 |
| 17 | Mikey Doble | Vauxhall/TOCA | 43.591 |
| 18 | Andrew Watson | Vauxhall/TOCA | 43.899 |
| 19 | Aiden Moffat | Honda | 48.238 |
| 20 | Dexter Patterson | Cupra/TOCA | 48.429 |
| 21 | Jack Butel | Cupra/TOCA | 49.702 |
| 22 | Will Powell | Honda | 57.327 |
| 23 | Nicolas Hamilton | Cupra/TOCA | 57.986 |
| 24 | Tom Chilton | Hyundai | 1'02.401 |
| 25 | Jade Edwards | Cupra/TOCA | 1'03.750 |
| 26 | Nick Halstead | Hyundai | 1'12.115 |
| (5) | Ricky Collard | Toyota | Retirement |
