On 15 minutes, the seven scratch riders were quickly reduced to five when Phil Groves tested the bunch on the first climb up Western Line dropping both Gareth and James Wright.
This left Groves with Paul Forrest, Mark Armstrong, Matt Goode and Brian Scrimshaw for company.
The gaps closed slowly as the race wore on, with the stronger riders making ground steadily on the Western Line climb and on the stretch of Brunswick Rd exposed to the difficult crosswind.
The five remaining in the scratch bunch finally caught McNeill's break bunch, two-thirds of the way up the final ascent of Western Line.
With Groves applying the heat, he and Goode had created a gap over most of their rivals by the top of the climb.
However, up front Chambers and Manson had gone for gold after dropping Weir earlier and the duo were still well clear on the long run in to the finish at Brunswick Hall.
As Manson went to wind up for the sprint finish at several hundred metres remaining he clipped Chambers rear wheel in the windy conditions and hit the deck.
Sportingly, Chambers paused to check on his rival, but once assured his injuries were not life-threatening carried on for a convincing win.
Manson showed courage to pick himself up for a blood-stained and hard-earned second placing.
There was a gap of just over three minutes before Groves and Goode appeared, with Groves fighting hard to out sprint Goode for third. Groves also registered the day's quickest time at 1hr 13min 10sec.
Ross McNeill, who had stayed with Groves and Goode for a while after the last climb, was at the head of the next bunch to claim a handy fifth placing, with Lewis Bunker boxing on well just behind in sixth.
In the C grade race of 22km over two laps, Craig Bright's run of top form continued.
Bright rode through the field for an impressive win clocking the fastest time (46min 12sec) in the process.
Dean Blackwell faded on Brunswick Rd and crossed second, some 46sec in arrears. Craig Whittaker battled for third, with Paul Darby fourth.
Results
A&B; Grade, 44km handicap: Tim Chambers 1, Rob Manson 2, Phil Groves 3 (fastest time 1:13.10).
C Grade, 22km handicap: Craig Bright (fastest time 46.12) 1, Dean Blackwell 2, Craig Whittaker 3.