Ricciardo, who won in Azerbaijan earlier in the season, produced a brilliant performance at Marina Bay on Friday over both practice sessions as he put down an early marker to the rest of the field.
The Australian clocked a quickest time of 1:40.852 in P2, 0.556 seconds ahead of team-mate Max Verstappen in second, while Mercedes star Lewis Hamilton was almost a second slower than the early pacesetter in third.
Valtteri Bottas finished fourth for the Silver Arrows while Nico Hulkenberg enjoyed a fantastic day as he ended up in fifth for Renault, one of their best practice performances of the campaign.
Stoffel Vandoorne and Fernando Alonso were then sixth and seventh respectively for McLaren, whose split with engine-supplier Honda was confirmed on the opening day in Singapore.
Sergio Perez was eighth for Force India but the biggest surprise came in the shape of Ferrari, who endured a miserable time with Kimi Raikkonen and Sebastian Vettel only ninth and 11th respectively.