Lewis Hamilton edged out Max Verstappen to complete a clean sweep of Friday's practice sessions for the 2018 Formula 1 season's curtain-raising Australian Grand Prix.
Hamilton did not improve on his FP1 benchmark significantly but a 1m23.931s was good enough to keep for Mercedes ahead of Red Bull around Melbourne's Albert Park circuit.
The teams were more lethargic hitting the track in FP2, with Kevin Magnussen the first to venture out four minutes in, but flying laps kicked in almost immediately afterwards.
Verstappen fired the first real statement of intent after 10 minutes with a 1m25.063s on soft tyres, which Valtteri Bottas beat by three tenths of a second in his soft-shod Mercedes.
Hamilton usurped top spot soon after on a 1m24.569s and went quicker on his second run on a set of supersofts to get down to a 1m24.385s.
Verstappen then lapped only 0.016s slower, still on softs, while it took a set of ultrasoft tyres for Kimi Raikkonen to vault Ferrari ahead of both on a 1m24.214s after 35 minutes of running.
Hamilton moved back ahead within a matter of seconds as he switched to the softest-compound Pirellis and broke the 1m24s barrier with a 1m23.931s.
Bottas then briefly made it a Mercedes one-two, but Red Bull then gave Verstappen a set of ultrasofts and he stole into the 0.228s gap between the W09s.
Raikkonen was shuffled back to fourth, 0.283s off the pace and a couple of tenths clear of Sebastian Vettel.
Daniel Ricciardo was poised to emphasise Red Bull's position as Mercedes' closest challenger until a red flag halfway through the session ruined a hot lap.
Ricciardo was just 0.110s slower than Verstappen after the first two sectors before loose wire on the start-finish straight triggered a brief stoppage.
The session resumed swiftly but by this point the frontrunners had completed their qualifying simulations, which meant attention turned to long runs and there were no more changes at the top.
Ricciardo's aborted flying lap allowed Romain Grosjean to cap a very impressive opening day of the season for the Haas team with sixth place.
Haas was one of the understated stars of pre-season testing and Grosjean's 1m24.648s, just 0.717s slower than Hamilton, put the American team comfortably clear of its midfield rivals.
Haas's half-second advantage over the midfield was at odds with an otherwise ultra-close fight contested by the Woking team, Renault, Force India, Williams and Toro Rosso.
Less than a second covered Alonso in eighth and Sergey Sirotkin in 18th, but Sauber ended the day adrift at the foot of the times.
Marcus Ericsson pipped Formula 2 champion and F1 debutant Charles Leclerc by just 0.001s, but both drivers lapped 0.8s slower than the rest of the field.
The session ended with Lance Stroll having to stop his Williams on track after hitting trouble.
|2||Max Verstappen||Red Bull||TAG||34||1'24.058||0.127|
|7||Daniel Ricciardo||Red Bull||TAG||28||1'24.721||0.790|
|11||Carlos Sainz Jr.||Renault||Renault||35||1'25.390||1.459|
|12||Sergio Perez||Force India||Mercedes||30||1'25.413||1.482|
|15||Esteban Ocon||Force India||Mercedes||33||1'25.888||1.957|
|16||Brendon Hartley||Toro Rosso||Honda||41||1'25.925||1.994|
|17||Pierre Gasly||Toro Rosso||Honda||39||1'25.945||2.014|