Chignell decided to use the 10km event, which is run as an open interclub race every five years by the Caversham club, as part of her build-up for next month's 100km event in Naseby.
She was also inspired by son Oliver's victories in age-group races held around Brighton.
When handed what she thought was a generous handicap of 10min 30sec, her initial approach was to cruise and see what happened, but the presence of Kylie Batten (Taieri) quickly caused her to change her tactics.
Batten made her intentions clear with some aggressive running over the unforgiving terrain, and she overtook front marker Helen Collins (Hill City) on the rise through Waldronville.
Chignell tried to stay with Batten, who was surging away on the uphill but falling back on the downhill.
As Chignell overtook Collins at the top of the rise at Waldronville, she used her strength on the downhill to overtake Batten and pull away, and crossed the finishing line 25 seconds clear of second-placed Batten in an actual running time of 47min 22sec.
Chignell, a Dunedin doctor, is no stranger to road races, having won the women's section of the Port Chalmers to Dunedin race four years ago.
She also won the women's section of the 80km race associated with the Naseby event last year.
Bill Houston (Ariki) overcame a disrupted start to finish third overall and lead the men's field across the line.
Houston recorded an actual time of 45min 30sec from a handicap of 44min.
Anna-Lisa Uttley (Hill City) gave the 1987 course record for women of 35min 50sec a fright, when she finished just seven seconds shy of the mark.
Uttley, who will compete in the 3000m at the Youth Olympics in Singapore next month, recently returned to Dunedin to further her education.
A nagging headwind perhaps put paid to any real threat to Alan Thurlow's 1977 record of 29min 36sec, but Bevan Stevens (Caversham) nevertheless backed up his Edmond Cup victory by recording an impressive 30min 56sec, 23 seconds clear of clubmates Daniel Balchin and Tony Payne.
There was an impressive performance from Rosie Robinson (Hill City), who race-walked the course in 50min 28sec.
