Lewis Hamilton has set an eye-catching pace on the penultimate day of pre-season testing in Barcelona.
The Mercedes driver set a lap of one minute 20.558 seconds - the fastest time of the winter so far and 0.708 seconds clear of Ferrari's Felipe Massa in second.
Force India's Adrian Sutil was third, ahead of Pastor Maldonado's Williams.
Hamilton's pace prompted BBC F1 technical analyst Gary Anderson to predict he could win the 2013 title.
"Some of the lap times we've seen already from Mercedes have been pretty good but that one is pretty impressive," Anderson said. "I think they have the talents to win races and win the championship this year."
Hamilton, who has admitted he does not want to get his team's hopes up, said: "I don't think there is any need to be impressed.
"It is important to bring everyone back down to earth and realise we still have a lot of work to do.
"Mercedes are doing a great job in the engine department and the car. But we have not seen Jenson (Button), Sebastian (Vettel) or (Fernando) Alonso in the car today.
"It's everything to play for still. We won't know until the first race but don't be surprised if we get to the first race and were not at the front.
"We have got through everything and we are not in deep, deep trouble. We're going in the right direction."
Asked if he thought he could win the title, he said: "It's not no chance and it's not definitely we will. I think we definitely will be able to win a race at some point in the season. I hope we can at least. But when that will be, who knows?"
Red Bull's Mark Webber said: "It was a good time, yeah. But Merc have done that a few times in the winter."
That is a reference to last year, when Mercedes started the season well but tailed off dramatically in the second half of the season.
Hamilton set his time in the morning session at the Circuit de Catalunya and in all completed three laps all in the 1m20s bracket and faster than anyone else managed on the day.
Massa had been third fastest in the morning behind Sutil but edged closer to Hamilton's best time with some short runs in the afternoon.
He got down to a 1:21.457 on the same 'soft' tyres that Hamilton used for his run, but then lowered that to a 1:21.359 and then a 1:21.266 using the 'super-softs'.
The Brazilian was the only driver able to keep the softest tyres in good shape for long enough around a whole lap to benefit from their greater grip to set a faster lap time.
His day ended prematurely just after he set his fastest time when a front wheel came off and he had to stop out on the circuit.
Lap times in testing are notoriously poor indicators of true form for the season ahead because it is impossible to know the fuel load in each car - and 10kg of fuel (about 14 litres) equates to 0.38secs a lap around the Circuit de Catalunya.
But there is no doubt that Hamilton's performance was impressive.
No other team has conclusively proved it can do that sort of time - although given an understanding of how teams run their winter programmes and from looking at the cars on track it seems likely that Red Bull, Lotus and Ferrari and probably McLaren, too, are similarly competitive.
Several of the teams had significant updates on their cars.
The Ferrari had a new front wing endplate and exhaust/rear bodywork and Williams had a Red Bull-style rear bodywork design. Red Bull themselves also had a new front wing.
Williams's Valtteri Bottas was fifth ahead of Sauber's Esteban Gutierrez, Red Bull's Mark Webber, Sergio Perez's McLaren and Toro Rosso's Jean-Eric Vergne.
Lotus had to fly Romain Grosjean back from Paris after Kimi Raikkonen, who was scheduled to drive had to miss the test because of illness.
Italian Davide Valsecchi drove the car in the morning until Grosjean could get in it after lunch.
Grosjean ended the day 10th fastest, narrowly ahead of Valsecchi.
Frenchman Jules Bianchi had his first run in the Marussia after signing as a late replacement for Brazilian Luiz Razia, dropped following a dispute over sponsorship payments.
Bianchi impressed with ninth fastest time, 0.8secs faster than his team-mate Max Chilton had managed so far at this track this winter. He was also faster than Giedo van der Garde's Caterham, the team's back-of-the-grid rivals.
FINAL PRE-SEASON TEST, CIRCUIT DE CATALUNYA, DAY THREE, FASTEST TIMES
1. Lewis Hamilton (GB) Mercedes 1:20.558
2. Felipe Massa (Brz) Ferrari 1:21.266
3. Adrian Sutil (Ger) Force India-Mercedes 1:21.627
4. Pastor Maldonado (Ven) Williams-Renault 1:22.305
5. Valtteri Bottas (Fin) Williams-Renault 1:22.468
6. Esteban Gutierrez (Mex) Sauber-Ferrari 1:22.553
7. Mark Webber (Aus) Red Bull-Renault 1:22.658
8. Sergio Perez (Mex) McLaren-Mercedes 1:22.694
9. Jean-Eric Vergne (Fra) Toro Rosso-Ferrari 1:23.223
10. Romain Grosjean (Fra) Lotus-Renault 1:23.380
11. Davide Valsecchi (Ita) Lotus-Renault 1:23.448
12. Jules Bianchi (Fra) Marussia-Cosworth 1:24.028
13. Giedo van der Garde (Ned) Caterham-Renault 1:24.520