The 20-year-old handed Philippe Clement’s team all the points at stake with 21 minutes left to play at Jan Breydel Stadium.
Club Brugge began the encounter on a bright note with Percy Tau almost putting them ahead after one minute. The South African found his way into the opponents’ goal area but his low shot missed the target after displacing three defenders.
Two minutes later, Emmanuel Dennis missed the target as his long strike failed to threaten goalkeeper Pieter Gerkens.
Despite their early attacking surge, it was Anderlecht who took a fifth-minute lead after Nacer Chadli profited from clumsy defending to fire into an empty net.
However, their lead lasted for just one minute as Hendrik Van Crombrugge deflected Diatta’s shot into his own net after it had kissed the woodwork.
Tau missed another golden opportunity in the 13th minute, and the score remained 1-1 at half-time.
With the tie heading for a draw, Diatta scored the winner after slotting home from close range before making way for David Okereke in the 90th minute, as well as Tau for Siebe Schrijvers.
Following their latest victory, they sit second in the log with 17 points after seven games. Clement’s side square up against Francs Borains in a Cup game on Wednesday.