Running at the venue for the first time, the Victory AC member won in 17.27.
Southsea is the 14th different parkrun - out of 16 - that Gill has claimed first place in, including one in Poland.
Martin Stockley (Eastleigh RC) was runner-up in 17.51, while Portsmouth’s junior 11-14 age group runner Cameron Walker-Powell was third in 18.12.
Mohammed Abdalla (JM 15-17 category) was seventh in a new pb of 18.45, while City of Portsmouth AC’s ninth-placed Emma Jolley was the first woman to finish in 19.28.
Chris Wheeler (Stubbington Green) claimed a new pb in 22.56 (51st).
Julian Manning (Denmead Striders) won the 177th Lakeside parkrun in 19.09 - his sixth victory in his last nine attempts at the venue.
Luke Brocks (Haslemere AC) was 16 seconds adrift as runner-up with Horsham’s Raff Vitale third on his first Lakeside outing in 19.27.
Portsmouth Joggers’ Phil Guest - competing in the veteran 60-64 category - was fifth in 19.34
Denmead’s Tillie Johnston equalled her personal best time in finishing 21st in 21.34 - the first woman to finish.
Numbers 25-29 all recorded new pbs - Ethan Hall (21.48), Paul Barrett (21.51), Daniel Holden (21.53), Shaun Morris (Portsmouth Joggers, 21.55) and Kevin Rowsell (Baffins Fitclub, 22.0).
Havant AC’s Harriet Burr was second woman to finish in 22.0.
Other Portsmouth Joggers club members recording pbs were Peter Turnbull (110th, 27.08), Sarah Tutt (111th, 27.09), Christina Brodie (193rd, 31.42), Elaine Martin (220th, 32.34), Rachael Smith (256th, 35.29) and Yvonne Morris (285th, 38.31).
Josh Chivers ran his 11th career parkrun at Havant - and claimed his first win in 18.48.
He was 47 seconds ahead of runner-up Callum Jones in the 385th staging of the event, with Victory AC’s Carl Jarmaine third in 20.21.
Jon Mills (20.25) and Shenzhen Newman (20.33) recorded pbs in finishing fourth and fifth respectively.
Victory pair Matt Gill (20.57) and Richard Turner (20.59) were sixth and seventh.
Another Victory member, Zoe Gill, was the first woman to finish in 20th - two seconds outside her pb in 22.20.
Baffins Fitclub member Richard Stevens recorded a new pb of 22.48 in finishing 25th.
Callum Aldous ended his run of second places with victory in the Fareham parkrun.
Runner-up on each of his previous three visits to the venue, the Bognor-based Tone Zone member triumphed in 17.53 - a new personal best.
Fareham Crusaders’ James Hughes was second in 18.28 and Storms Menri third in 18.51.
Stubbington Green’s David Mallard was fourth in 19.21 and clubmate Ray Gunner sixth in 19.38.
Hedge End Runners member Sophie Stoneham entered the Fareham event for the first time, and was first woman home in 22.50 (30th).
There were new pbs for Andy Richardson (Stubbington, 64th) in 25.09 and Fareham Crusaders’ Gill Matthews (competing in the vets 65-69 category) in 30.24.
Also running faster than ever was vet 55-59 category Chris Hastings (Highlands Practice) in 31.33.
Young Molly Collins (Highlands Practice, junior 11-14 category) also recorded a new pb of 45.0.
There were more personal bests as Leah Marshall (vets 45-49) and Rose Marshall (vets 70-74) finished in 50.02 and 50.04 respectively - the latter competing in only her fourth ever parkrun.
Stubbington Green’s Rob Greenwood claimed another parkrun win at Whiteley.
He finished in 17.31 - 47 seconds ahead of Max Powell (junior 15-17). It was Greenwood’s sixth Whiteley event and his third success.
There were six pbs in the top 10, a list headed by Josh Horner (junior 11-14) who was fourth in 18.34.
He was followed by Thomas Outen (19.16), Martin Chandler (19.27), Christy Cerny (19.27), Miles Horner (junior 11-14, 20.15) and first woman Lucy Harrison (Southampton AC, 20.34).
There were also pbs for Stubbington pair Richard Kimber (40th, 23.29) and Dave Judson (81st. 26.10).
Vikki Moxham claimed a top five finish in the Lee-on-the-Solent parkrun.
The Gosport Road Runners member was fifth in 18.54 - 23 seconds behind winner Darren Langridge (18.31).
Stubbington Green teenager Tommy Blake (15-17 category) was runner-up in 18.42.
Grace Park (junior 11-14 category, 21.22) was second female to finish in 24th place.
There was a new pb for Philip Armour (Fareham Crusaders, 47th) in 22.28 and Claire Hanrahan (Stubbington Green, 320th).
There was a bumper field of 501 finishers.