A riveting Tetley's Bitter Vase tie left Pegasus with just a scintillating opening try to compensate for a narrow loss.
Pegasus matched their hosts in every department, bar the scrummaging, which ultimately proved decisive.
Ongar appeared dominant for the First 20 minutes, but resolute defending denied them.
Then Pegasus scrum-half Mark Williams broke through his own 22 before releasing outside-centre Sam Taylor-Bryce who ran the rest of the pitch to place the ball under the posts for an easy conversion for fly-half Graham Wynch.
However, a five-yard scrum on the stroke of half-time led to a match-levelling try for Ongar.
Victory was sealed for the hosts when they took advantage of being awarded a second five-yard scrum to notch another converted try.
Pegasus launch their Eastern Counties Southern League Division Four season away to Loughton this Saturday.
Determined Richmond win through
WESTCLIFF COLTS 12
RICHMOND COLTS 25
A determined display from Westcliff, who were without their two most experienced players through injury, included a strong second-half fightback against their much-vaunted visitors.
Richmond - were very strong in all phases - opened up a 20-0 lead in the first period.
However, after the interval, with Westcliff's four newcomers feeling more at home, the Aviation Way side deservedly battled their way into contention.
First, a a rolling move left James Argentieri with a 30-metre sprint to the line for the first try.
Then Peter Moffat was sent on his way to the line for the second, with Matt Anderson converting well from the touchline.
"It was not a bad performance," Westcliff manager Paul Charman said. "Richmond knew what they were doing, but in the second half we got going and came much more into the game."
Westcliff blitz Romford
WESTCLIFF UNDER 17s 45
ROMFORD & GIDEA PARK UNDER 17s 5
The opening minutes of this game set the stamp on what was to come with an inspired display by the Westcliff forwards.
They set up quick ruck ball and two or three moves later, Simon Jones was clear for a 30-metre sprint to the line.
Soon afterwards Patric Redding scored the first of his two tries. Then good driving by the forwards allowed him to break free and canter over. Both scores were converted by Michael Pitt.
The fourth try came after more interplay between forwards and backs, enabling hooker Joe Duncombe to touch down, and further good combined work saw Jonathan Fozard touch down, Pitt converting both.
Westcliff's forward domination was constant now and skipper Brett McGarrigle twice crossed for tries, Pitt succeeding in one of his conversion attempts.
Converted for the new archive on 19 November 2001. Some images and formatting may have been lost in the conversion.
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