Lewis Hamilton is favorite to win the Spanish Grand Prix for a fourth time, and third in a row, on Sunday and retake the Formula One world championship lead from Mercedes team mate Valtteri Bottas. Needless to say, Ferrari have another script in mind for a race seen as something of a litmus test for their title prospects. Sebastian Vettel and Charles Leclerc dominated pre-season testing at Barcelona's Circuit de Catalunya amid excited talk of Ferrari ending Mercedes' five-year stranglehold on the sport. They return reeling from four successive Mercedes one-two finishes, an unprecedented start to the season by any team, and hoping an engine upgrade — brought forward by two races — will swing things their way. If Mercedes are again quicker at such a benchmark circuit, where the champions have won four times in the last five years, the writing will be on the wall for Ferrari. They need to step up a gear and start turning things around. Both teams have been talking up the other's chances. "The last four races, on average, we were not quite there so I think we are not the favorites going to Barcelona," said Vettel, winner with Red Bull in 2011, after finishing third in Azerbaijan. Team principal Mattia Binotto agreed: "Obviously Mercedes are very strong at the moment. I'm pretty sure they will be very strong as well in Barcelona. "Many teams will bring aero package or car developments, so that will be again a different balance compared to what we've seen so far in the season," he added. Mercedes principal Toto Wolff dismissed Vettel's portrayal of Ferrari as underdogs for the first race of the European season. "The results seem to paint a relatively clear picture, but the truth is that they're too flattering. The performance has fluctuated in the first four races," said the Austrian. "Our opponents were blisteringly quick in winter testing, so the Spanish Grand Prix will be anything but easy." Bottas leads five times world champion Hamilton by a single point, with both men on two wins, by virtue of the Finn's fastest lap in the Australian season opener. British bookmakers William Hill have Hamilton as race favorite at 6-4, with Bottas on 9-4 and Vettel and Leclerc priced at 9-2. Barcelona has also been a happy hunting ground for Red Bull, with Max Verstappen becoming the sport's youngest winner there in 2016. "It is always a special one for me," said the 21-year-old of a track whose future remains uncertain, with talk of Verstappen's home Dutch circuit Zandvoort taking the slot next year. "The temperatures will be a bit different (to testing in March) and everyone is bringing new parts to their cars, so it will be interesting to see how competitive we can be." Former Red Bull teammate Daniel Ricciardo, now at Renault, has a three-place grid drop as punishment for a bizarre collision with Toro Rosso's Daniil Kvyat in Baku. A Brazilian-Austrian flag will be displayed on the podium in tribute to the late triple champion Ayrton Senna and Roland Ratzenberger who died at Imola in May 25 years ago. Sunday's race is the first since the anniversary. — Reuters
