The Newport star is still focusing on his bid for World Supersport 300 glory but used his spare time to compete at Donington Park for the opening round of the British series.
The 24-year-old nearly returned with a 100 per cent record too after claiming three wins, with a single second place the only slight blemish of his weekend.
He said: "Kawasaki asked me to do it just to keep up to speed in my summer break.
"I just rode a standard bike I use to train, with no team behind me – it was just me and my mates running it.
"I might do some more as it would be cool to try win a British and world championship in same year. It was nice to be back."
Booth-Amos claimed a dominating win in the opening race of the Hel British Junior Supersport Championship, scoring the victory by more than 12 seconds in a wet season opener.
He then held off an attack from Cameron Dawson on the final lap of the second race to double up on victories.
Kam Dixon claimed the third race win of the weekend, following an incredible race-long duel for supremacy in the leading pack.
Booth-Amos eventually made his way to the front and began trading blows with Adon Davie, who later dropped out of the race, as well as Dixon.
Dixon had the advantage though when the race was red flagged for rain, giving the Affinity Sports Academy Kawasaki rider the victory
But Booth-Amos again added to his winning tally in the final race of the weekend, holding off Cameron Dawson to extend his advantage at the top of the standings, with 95 points.
Dixon sits second on 60 points with Cameron Dawson third on 50.
Shrewsbury sidecar passenger Tom Bryant was also out in action over the weekend at Donington after signing up to race in the Superside World Championshi as a wild card.
Bryant was back with Philp Racing F1 Sidecar Team – and driver, Tommy Philp – with the pair were looking to build on their impressive podium during the opening British Sidecar round at Oulton Park.
And after struggling in race one, they regrouped to score a superb fourth-placed finish in the second.
Bryant said: "We unfortunately had a coming together on lap one of the opening race, which saw us changing wheel arch in the pits and get back out.
"However, we had damaged the wheel and pulled in resulting in a DNF.
"But we had a great second race and were in sixth position for a few laps.
"Once we got past the outfit in front our lap times got quicker and quicker.
"On the penultimate lap, we caught fourth place and that's where we finished.
"Thanks to all of our sponsors for getting us on the grid: Roberts Constructions, PS Higgins Electrical Services Ltd, Hoval, Studio 997, Repair Care International UK, Mark's Autocare Ltd, Rock Oil, NGK Spark Plugs, Turbo Toms Autos, INSX pest control, Draper Ventilation, Airport services, Life Safety Systems and Whites of Windsor."
Mid Wales star Chaz Davies was back out in full World Superbike action at Donington Park and came away from round four with some mixed results, which leaves him ninth in the championship standings.
The Team Go Eleven rider was greeted with rain, sun and mixed weather conditions during free practice and eventually qualified ninth for race one.
Shortly before the flag dropped, the sun made its appearance, quickly drying the track, which meant all the riders decided to out on slick tyres.
The 34-year-old took a few laps to get dialled with the track's new asphalt, losing time at the start of the race.
But whilst fighting for ninth position, the pain in his shoulder – following two big crashes in the previous round – became too strong, which forced him to settle for 11th.
The track was again wet for Sunday's points-scoring Superpole race and Davies was able to claim a solid eighth place.
Dry conditions finally returned for race two but Davies slipped back to 14th before finding his rhythm.
After setting a lap time of 1.28.770 – faster than the riders fighting for the podium places – he climbed back up to seventh, which will give him confidence going into round five at TT-Circuit Assen, in Holland, July 23-25.
Davies said: "I was really happy with race two. I felt physically better on the bike.
"I'm still struggling but definitively had enough to be able to fight until the end of the race, which was what it has been missing in yesterday's (Saturday's) race and a bit even in the Superpole.
"I think we did a good job and we salvaged the weekend, considering our situation. It was positive ahead of Assen."
Booth-Amos now returns to World Supersport 300 action, along with Davies, at Assen while Bryant heads to Knockhill, in Scotland, for round two of the British Sidecar series this weekend.