He finished tenth out of the 8,000 runners in a new club record time of 2hr 35min 19sec.
Twenty members of the Chichester club are due to run spring marathons this year – the first half of the group lined up at Brighton with the remainder in action in London this weekend.
At the head of the race, it was an all-African affair with Kenyans Philemon Kiprop-boit and Richard Rotich just getting the better of Ambessa Tolossa from Ethiopia with all three finishing between 2hr 16 and 2hr 17.
Showing the quality of the field, Olympian Dan Robinson from Stroud was next home in just over 2hr 19min, a few seconds slower than last year’s course record.
Baker’s tactics were to stay with a group at just under six-minute miling pace and the Chichester man followed this strategy to perfection, going through ten miles in 58 minutes and 20 in 1.56.
Going round the Shoreham docks area at 22 miles, Baker passed Robbie James of Lewes AC, a sub 2hr 30 runner, to become the first Sussex runner on the road.
Baker (right) managed a tough and very hot last 10k in just over 39 minutes to knock no less than seven minutes off his only previous marathon, set in the same event last year.
Troubled by a niggling injury during the past few weeks, Baker has been forced to limit his training to ‘only’ 40 miles a week but he has kept up his fitness by competing regularly at shorter distances to sharpen his in-built endurance forged by many weeks of 80 to 100 miles over the winter.
Behind Baker at Brighton, one of Chichester’s best over-50 veteran runners, Dave Dorning, was pleased with a 3hr 10min clocking for a creditable 118th place overall – high up in his category.
Dan Turner was next home in 3.21 and 279th place, knocking no less than 20 minutes from his 2010 time.
Three more finished inside the four-hour barrier with Matthew Sheldon home in 3.47, Mark Jennings 3.49 and Terry Healy 3.54.
Fiona Lewis came home in a fine 4hr 5min to lead Chichester’s ladies with Felicity Paton next in 4.18 and Catherine Betts 4.32, with Sally Humphrey just behind.
This Sunday’s London event looks as though it may benefit from cooler conditions, with James Pennicott likely to lead home the Chichester field if he has shaken off a recent injury.
n Juniors and seniors in the club will be turning their attention to shorter distances in the Sussex road relays at Christ’s Hospital School, Horsham, on Easter Saturday. The juniors will be running a lap of just under 2,000m while seniors, veterans, under-17s and under-20s will be doing battle over a fast lap of just over two miles.