The Australian driver, who has made a bright start to his first season with Red Bull, was quickest in damp conditions on Saturday.
Ricciardo's time of one minute, 53.958 seconds was fastest at the Shanghai International Circuit as several big guns barely appeared.
Williams' Felipe Massa (+0.534s) and Lotus' Romain Grosjean (+0.556s) were the only drivers within a second of Ricciardo.
High-flying Mercedes, dominant this season, Ferrari and McLaren were pitted for most of the session, which was hampered by intermittent rain.
It leaves Ricciardo well-placed with wet weather also expected for qualifying later on Saturday.
Force India's Nico Hulkenberg (+1.074s), Ferrari's Kimi Raikkonen (+1.104s) and Lotus' Pastor Maldonado (+1.27s) made up the top six.
Behind them were Toro Rosso's Daniil Kvyat (+1.277s), Williams' Valtteri Bottas (+1.423s), McLaren's Jenson Button (+1.715s) and Force India's Sergio Perez (+2.061s).
Red Bull four-time defending champion Sebastian Vettel was 11th on the timesheet.