The winner of the opening inter-insular in a four-race series back in May, on the same Watersplash circuit but then finishing at the top of L’Etacq Hill, the veteran rider edged a sprint finish to beat Guernsey duo Mike Serafin and James Roe.
Senior rider Serafin lost out in a split-second finish, while fellow senior Roe, who won the second CI race in Guernsey, recorded exactly the same time as the leading pair – two hours, 36 minutes and 54 seconds.
Jersey’s Gold Coast 2018 Commonwealth rider Jack Rebours couldn’t quite keep up with the leaders and settled for fourth position, 30 seconds back, with Jordan Sewrey clocking the same time for fifth.
CASP rider Spence, who competed at the 1995 Island Games when it was last held in Gibraltar, said: ‘It was pleasing to win again and great to have competition from Guernsey riders.
‘The race committees of both islands have put this series together as part of their selection process for the Island Games , so it’s key to me doing well and it’s a good field.
‘I’m showing consistency and I like to think I do that every year.’
Roe’s chances of a second senior success looked good as he drove an initial breakaway within the first few miles of the 100 km course.
Serafin hung back on the break before surging along Five Mile Road on the second of four laps and rejoining the leaders by the half-way point, becoming a strong contender from then on.
Serafin took second by a tyre’s length from Spence, with Roe just behind.
The shorter women’s race was an all-Jersey affair.
Commonwealth Games rider Kim Ashton claimed yet another dominant win, from fellow home riders Florence Cox and Louise Woolrich respectively.
Over the same distance, Tony Bleasdale yet again proved Guernsey’s big draw by defying the Jersey competition and gaining his third consecutive veterans’ success. Leading Jersey riders were Mark Smith and David Vieira in third and fourth position respectively.
The final CI Series race is in Guernsey on 26 August, the same weekend that Guernsey Vélo Club celebrate their 50th anniversary.