George Russell expects it to be a 'tight' battle between the top teams in the Singapore Grand Prix, as he predicted even more potential from Ferrari was yet to come.
The Briton was third quickest at the end of FP2 when teams ran the Soft tyre, just 0.126s off the best time set by Carlos Sainz.
Fernando Alonso split both the Mercedes drivers, with Lewis Hamilton setting the fifth quickest time that was four-tenths off the pace.
Despite encouraging signs, Russell expects there is more to come from Ferrari when speaking to F1 TV: "They are looking favourites at the moment, I don't think they're maximising their power units that much," he said.
"They've probably got a couple of tenths in their pocket, so the fight is still on for the second row.
"The tyres are key, because getting it into the sweet spot you can find tenths of a second easily. So we just need to find that sweet spot.
"The long-run performance across a number of competitors was also strong but we can be optimistic heading into the weekend."
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Red Bull 'didn't look like the ones to beat'
Usual front runners Red Bull were seven tenths off the pace, after both Sergio Perez and Max Verstappen complained of balance issues.
"The performance order is interesting today. Ferrari looked fast, as do McLaren and Aston Martin and unusually Red Bull didn’t look like the ones to beat," said Mercedes Trackside Engineering Director Andrew Shovlin.
"We’ll assume that they’ll sort that out for tomorrow, which is going to mean that a lot of drivers are fighting for the top grid spots.
"It’s clearly very close so we’ll be pushing to find every little bit of pace overnight. We’re looking forward to an exciting qualifying session."