Brewster took another significant step in his recovery from long-term injury with a 45-minute appearance at the Kirkby Academy that represented his first outing since January 2018.
Watch: Brewster's brace on U23s comeback
Alex Oxlade-Chamberlain was among those in attendance and watched the striker open the scoring after six minutes with a curling effort from outside the penalty area.
The 18-year-old then grabbed his second a short while later by converting the rebound of a Glen McAuley shot that struck the crossbar.
Brewster, who signed a long-term contract with the club last July, played the entire first half of an eventual 4-0 win for Neil Critchley's side.
Left-back Tony Gallacher also claimed a double with two finishes from close range in the match's final minutes.
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