Singh, 21, joined Chaves on a six-month loan deal from title-chasing Braga when the transfer window opened on January 1.
After netting 14 goals and registering nine assists in 52 appearances in the Portuguese second division, the talented winger opted for a temporary spell away in a bid to gain first-team exposure to further his development.
And the former GAIS man made an instant impact at the relegation-threatened side, despite the game ending in a 0-0 stalemate against CD Feirense.
Singh was a constant menace starring in a right-wing role and provided the attacking impetus that was previously lacking in the Flavienses over the course of the 2018/19 season.
He finished the encounter with five shots on target, 80% pass success rate and completed all four of his attempted dribbles.
The South African will now be aiming to gain a regular run of first-team football and propel the 18th placed side to safety.