Ferrari's Fernando Alonso set the pace in the first practice session at the Chinese Grand Prix on Friday, indicating the struggling team could emerge as a challenger to dominant Mercedes in Sunday's race.

Alonso set a best time of 1 minute, 39.783 seconds around the Shanghai International Circuit, nearly 0.4 seconds faster than Mercedes' Nico Rosberg in second. Red Bull's Daniel Ricciardo was third, nearly a full second behind Alonso.

Mercedes have won all three races this season, with Lewis Hamilton taking two and Rosberg one. Alonso, meanwhile, has managed no better than a pair of fourth-place finishes.

Hamilton was eighth-fastest in Friday's practice, just ahead of four-time defending world champion Sebastian Vettel of Red Bull in ninth.