It is the second fastest time de Mauny has ever recorded and she led from gun to tape, stretching out her lead throughout the second of the two laps with an emphatic winning margin of three seconds.
De Mauny was far from finished as she had a full week of races and followed up by racing in the 400m and then the 1500m.
After safely negotiating her 400m heat in second place later the same day that she had won the 800m final, de Mauny went on to place fourth in the final last Friday with an incredible run for the line which saw her move from last place around the final bend to almost catching the third-place finisher.
She can be very happy with two PBs as her 58.22 in the final followed a previous PB of 58.46 in the semi-final.
Then came the 1,500m on Saturday and Sunday with qualification in second place in her heat in one of her fastest times of the season, followed up by a fabulous run in the final to win silver.
De Mauny’s time in the final was another season’s best and her second fastest time ever – 4:37.44.
A wonderful week was rounded off by running first leg in the Great Britain W35 4x100m relay team, her eighth race in seven days.
Simon Coombes placed sixth in the M45 1,500m final and was right in the mix until the last 40m or so with a great competitive effort.
M70 athlete Mike Mann placed 12th in his 1,500m final in a season’s best time of 5:45.06. Francis Marsh, in the colours of Ireland, missed out on a place in the M50 1,500m final by only 0.08 with his 4:26.59 in his heat.
Sprinter Giuseppe Minetti made it through the heats into the semi-finals of both the M45 100m and 200m, running 11.92 in his 100m heat and 12.05 in the semi, plus 24.34 and 24.31 in the 200m heats and semi respectively.
Herne Hill senior women and M50 teams were both crowned as county champions at the Surrey Road Relays at Wimbledon Park.
Helena Corbin, Stacy Macpherson, Katie Balme and Steph McCall formed the winning women’s team with the latter using her experience to move up from fourth to first on the anchor leg in her road racing debut for the Herne Hill team.
Ella Newton and Shannon Sinclair both posted good times in the B team. Newton is a Kent-qualified athlete, not Surrey, hence her appearance in a non-scoring B team with a time faster than any of the winning A team runners.
The M50 team returned to winning ways with Gary Ironmonger, Mike Boyle, Jonathan Ratcliffe and Derek Lee forming the victorious quartet.
There were also strong runs among the M40 and senior men with Jack Brotchie, Robin Jones, Jack Dickenson and Ed Crowther among those running decent times around the testing three-mile course, with the M40 team of Jones, Gavern Newsum, Robin Sanderson and Oliver Morrison placing fourth in their age category.
Some Herne Hill youngsters raced at the Will Bolton Memorial Cross Country relays at Sparrows Den in Hayes. The U15 girls team of Phoebe Bowen, Tilly Stevens-Cox and Sophie Williams placed second, while the U13 girls team of Roaslie Laban, Annabella Bailey and Izzy Perry were third.