The Chichester Runners AC member, a serial winner of local races across a variety of distances, clocked 16.32 - almost six minutes ahead of runner-up Paul Ayre (Lonely Goat, 22.25) in a field of 77 runners.
It was Baker’s eighth parkrun - at seven different venues - in 2022 and he has won all of them.
His latest time wasn’t his fastest 5k of the year, though; that came in winning at Southsea (15.45) in January.
James Broomfield (22.47) and Keith Loudon (Portsmouth Triathletes, 22.56) were third and fourth with Sam Morris (Denmead Striders) the first woman home in fifth place (23.29).
Gianni Shipp recorded his second race win in 34 attempts at Southsea, clocking 17.57 on the seafront course.
He was almost a minute ahead of Victory AC’s Andrew Meredith (18.49) in a 368-strong field.
In his first ever parkrun, Jacob Seal was third - just a second behind Meredith.
Gemma Brookes was first female home in a time of 23.00 for 43rd place - six seconds ahead of Maria Hazzard (Ealing Eagles).
Tim Rolfe (Stubbington Green) enjoyed his first visit to the Portsmouth Lakeside parkrun course.
In a field of 236, he was first back in a time of 18.05 - 51 seconds ahead of runner-up Kris Nicholson.
Victory AC’s Richard Turner - a veteran of 368 parkruns - was fifth in 19.39.
Nikki Moxham (Gosport Road Runners) was first woman back, finishing seventh in 19.50, ahead of Daisy McClements (Stubbington) who was 17th (21.36).
Teenager Joe O’Brien was easily the fastest finisher in the latest Havant parkrun at Staunton Country Park.
The Havant AC member, running in the junior male 15-17 category, clocked 19.00 - 94 seconds ahead of runner-up David Sear. Denmead’s Chris Cornwall was a further four seconds adrift in third.
There were two women in the top ten, led by seventh-placed Marjorie Huet-Martin (Emsworth Joggers) who finished in 21.26. Kirsty Aked (Denmead) was next home, six seconds later.
Showing parkrun is for all ages, City of Portsmouth’s Reginald Bailey competed in the male 80-84 category. In his 279th parkrun, he finished in 58.23.
Christopher Pearce (Defence Sports & Recreation) finished first at Fareham, clocking 18.15. It was his third parkrun victory at Cams Alders this year.
Stubbington Green’s David Mallard was second (19.37) while Edinburgh AC’s James Latham was third (19.42).
Eleanor Purdue (City of Portsmouth AC) was first woman home in 21.44 for 14th place.
Hastings AC’s Scott Crombie was first out of the 365-strong field to finish at Lee-on-the-Solent in 17.11. Thomas Wallace (17.29) and Luke Willis (Gosport Road Runners, 17.43) were second and third.
Stubbington’s Lucy May was first female back, clocking 21.40 for 32nd place.
Netley Abbey’s Holly Matthews was next (22.11 for 41st place).
Teenager Ethan Neale (Worthing Harriers) was first home in the 176th staging of the Whiteley parkrun. His 17.54 time was 59 seconds quicker than second-placed Simon Bittlestone.
Running at Whiteley for the first time, youngster Emerson Churcher was first female to finish. The Southampton AC member - competing in the junior girls 11-14 category - clocked 20.52 for ninth place.
The next best female, Tracy Shepperd (Hedge End), was a full two minutes behind in 31st place in a field of 203.