The Real Madrid superstar headed an early winner as Portugal edged out Morocco on Wednesday, putting the Euro 2016 champions within a point of qualifying for the knockout stages.
Following his hat-trick in Friday's pulsating 3-3 Group B draw with Spain, Ronaldo is leading the race to win the World Cup Golden Boot.
Ronaldo displayed new facial hair for the game and revealed the inspiration for the goatee in his post-match press conference.
Portugal's captain said: "This goatee? It's a joke I had with [Ricardo] Quaresma.
"We were in the sauna [before Friday's match against Spain] and I started to shave and I left the goatee - I said if I score tomorrow I would leave it for the rest of the tournament.
"And it gave me luck, I scored that game, I scored this one, so it stays."
— FIFA World Cup (@FIFAWorldCup) June 20, 2018