The 31-year-old has been plagued by injury in the last 18 months but netted his first goal for almost three years, a left-footed volley in a 2-1 win at Whaddon Road.
Speaking to the club's official website, Richardson said: "Everybody knows that I've worked hard for the past year to get fit.
"Now I'm getting fitter and back to the standard I was at.
"I've been able to play a few games and to get a goal like that is great.
"I just closed my eyes and hit it!"