MELBOURNE, Australia -- Sebastian Vettel topped the final practice session ahead of qualifying for the Australian Grand Prix, giving hope that Ferrari might be able to take the battle to Mercedes at the opening round of the season.
Vettel was 0.479s clear of Mercedes' Valtteri Bottas in second as Ferrari upped its pace by 0.8s compared to Friday practice. However, the final runs of the session, which are traditionally the quickest, were cut short by a red flag in the ten minutes from the end after 18-year-old rookie Lance Stroll wrecked his Williams against the wall at the exit of Turn 10. As a result, the true competitive order ahead of this afternoon's qualifying session remains vague.
Vettel set his time on a fresh set of ultra-soft tyres 40 minutes into the session on what looked like a qualifying simulation. He improved by 0.6s on his previous best of the session -- also set on the ultra-softs -- and held a 0.6s advantage over teammate Kimi Raikkonen, whose first ultra-soft run was cut short by a puncture.
Mercedes reacted with ultra-soft runs of their own moments later, but Bottas could only manage a time 0.479s off Vettel after losing time in all three sectors to Vettel. Friday's pacesetter Lewis Hamilton was third fastest despite setting the fastest first sector, and finished 0.490s off Vettel by the end of the lap. A mistake in the second sector appeared to put him off his stride and he ran slightly wide at Turn 13 in the final sector, losing nearly half a second across both sectors combined.
There was a full second between Raikkonen in fourth and Renault's Nico Hulkenberg in fifth, which is a gap Red Bull would usually be expected to fill. Instead, Daniel Ricciardo was 1.7s off the pace of Vettel after his second attempt at a flying lap on the ultra-softs was cut short when the red flags came out for Stroll's crash. Teammate Max Verstappen was another second off the pace after struggling to find a balance in the opening part of the session and running out of time at the end of the session to set a time on the ultra-softs.
Romain Grosjean finished seventh for Haas ahead of the two Toro Rossos and teammate Kevin Magnussen in tenth. Felipe Massa had to settle for 11th, but also failed to set a time on the ultra-soft tyres as he made up for lost time from his Friday gearbox issue. The Force Indias of Sergio Perez and Esteban Ocon were split by the McLarens of Fernando Alonso and Stoffel Vandoorne, but as was the case with most of the field, all three failed to set a competitive time on the ultra-softs.
Stroll was left down in 17th and was on his flying lap on the ultra-softs when he had his accident. He lost the rear of the car as he ran close to the wall on the exit of Turn 10, slamming the right-rear against the unforgiving concrete which in turn pivoted the front right into the same barrier. Williams will now work flat ahead of qualifying to repair the car, which requires a new gearbox and rear suspension assembly, new front suspension and a new front wing. The gearbox change will also result in a five-place penalty from wherever he qualifies.
Jolyon Palmer struggled to 19th, splitting the two Saubers at the bottom of the timesheets. Palmer's Renault was rebuilt following his accident on Friday and he complained of rear-end instability, a lack of bite from the brakes and a loss of power during the session. He finished just 0.263s ahead of Antonio Giovinazzi in the Sauber, who replaces the unfit Pascal Wehrlein at the team for the rest of the weekend.