The unit was retained after Mercedes personnel believed that the cylinder problem he encountered at the start of the last race had been rectified.
Hamilton took over at the top from Kimi Raikkonen, who had lapped his Ferrari in 1m 40.843s after expressing himself happier with the F14 T's balance than he had been in Albert Park. Interestingly, just as the Finn had gone fastest, team mate Fernando Alonso was busy spinning, as he became but one of many to discover that the green track required great finesse as everyone tried to tame their cars' rear ends. Or, in Hamilton's case, the front, after he understeered gently off the track right at the end. The Spaniard wound up 11th on 1m 41.923s.
Melbourne winner Nico Rosberg was third in the other Mercedes with 1m 41.028s, ahead of the McLarens of Jenson Button, with 1m 41.111s, and Kevin Magnussen on 1m 41.274s. The Dane had earlier set the pace, but trickled into the pits around the one-hour mark when he reported that his updated MP4-29 had lost power. An easily remedied sensor problem was subsequently diagnosed.
Jean-Eric Vergne's strong Australian form continued as he pushed his Toro Rosso to sixth with 1m 41.402s, which left him ahead of stablemate Sebastian Vettel on 1m 41.523s for Red Bull. Nico Hulkenberg put Force India into the top 10 with 1m 41.642s, while Felipe Massa headed Williams team mate Valtteri Bottas, 1m 41.686s to 1m 41.830s.
Behind Alonso, Daniel Ricciardo managed 1m 42.117s for Red Bull which left him ahead of Adrian Sutil's Sauber on 1m 42.365s, and Daniil Kvyat's decent form continued with 1m 42.869s for Toro Rosso as Esteban Gutierrez was 15th in the second Sauber on 1m 42.904s.
Jules Bianchi in 16th headed the Marussias, with 1m 43.825s to team mate Max Chilton's 18th best 1m 46.911s, while Caterham and Lotus both had troubled mornings. Kamui Kobayashi worked down to only 1m 51.180s before his Caterham's Renault energy store needed replacement yet again. Team mate Marcus Ericsson was thus left to uphold honour with 1m 45.775s for 17th place, but on the positive side he set the highest number of laps - 24.
Romain Grosjean's Lotus didn't even last its installation lap before the Frenchman pulled off with yet more mechanical woes and a subsequent run right at the end saw him bring the E22 straight back in. Pastor Maldonado meanwhile didn't get going until the final third of the session - and also rolled to halt in the pit entry after being told to kill his Renault power unit which had begun smoking heavily.
Everybody ran the Pirelli hard tyre in FP1, so if the weather remains dry the times can be expected to drop in FP2 when the teams sample the medium compound for the first time. For reference, the fastest time in practice last year was Vettel's 1m 36.435s.