Marcus's 32nd-minute deflected strike was his third in as many games against the French champions, and his sixth in total in the UEFA Champions League this season.
That tally sees him sit joint-first in the competition's top-scorer rankings, alongside Juventus centre-forward Alvaro Morata and Erling Braut Haaland, of Borussia Dortmund.
Rashford has scored, on average, a goal every 54 minutes in the tournament so far, compared to Haaland's 58 and Morata's 61.
Our no.10 also managed to do something no United player has achieved since Ruud van Nistelrooy, back in the 2004/05 season.
After his hat-trick at home to RB Leipzig, and last week's successfully converted penalty against Istanbul Basaksehir, Rashford has now scored in each of our three group-stage games played at Old Trafford this campaign.