Britain's fastest twins, kart racers Shaun and Matthew Arnold endured mixed fortunes in the latest rounds of the Formula One Management backed Formula Kart Stars Championship at their home track at Ellough Park in Beccles.

Although Shaun arrived at the third and fourth rounds of the championship with momentum on his side following a sensational wet weather victory in the second round at Kimbolton it was Matthew, the elder twin by 15 minutes, who finished the weekend with the best result of his FKS career to date.

The 15-year-old twins, currently studying GCSEs at East Bergholt High School, compete in the fiercely competitive 70mph junior rotax class in the same championship that helped launch Lewis Hamilton and Paul di Resta on the road to stardom. They had high expectations heading to the track where they began their karting careers.

While Shaun battled his way to a heat win it was Matthew, in his first year in the junior class, who ended the weekend on a high with a stunning drive from 19th to fifth in Sunday's final, earning praise from his team boss and a �125 voucher from Izone Driver Performance.

Following two challenging heat races Matthew qualified his Danny Cruttenden Motorsport Durapipe kart 11th for Sunday's 22-lap final but a crash in front of him at the first corner forced him into taking evasive action and he completed the opening lap in 19th place.

Matthew moved up and posting lap times that matched the leaders to get to ninth – before three karts ahead of him, including brother Shaun, collided and he squeezed through to take his first top five finish.

'I saw the group ahead battling and I knew if they continued to fight I would catch them. I passed two going into the hairpin when my brother got taken out and then got two more into the last corner,' he said.

Team boss Cruttenden, himself a multiple karting champion, said: 'Matthew's drive in the final was stunning. Shaun deserved a podium but we've got to take the positives from the weekend and Matt really proved he has plenty of raw pace.'

After finishing fourth in Saturday's final Shaun was on course for a podium on Sunday until the crash. Shaun still holds fifth in the overall championship standings while Matthew moves up four places to seventh overall with eight rounds left.