PARIS, France - Lewis Hamilton must keep the pressure on Sebastian Vettel at the 2013 Belgian Formula 1 GP to maintain his slim title chance.Ferrari has slipped off the pace in recent races, but Mercedes is at last adding consistency to its undoubted speed to give Hamilton an outside shot at closing the gap on championship leader Vettel.'PROVED EVERYONE WRONG'Hamilton, 2008 champion, is fourth overall and has nine races left and 48 points to make up on the defending champion but Mercedes has won three of the past five races and Hamilton has taken three consecutive pole starts - the most recent three weeks earlier when he drove superbly from the front to win the 2013 Hungarian GP in Budapest.Hamilton, who made a high-profile switch from McLaren, said: "It's a really positive season. Everybody was talking me down at the beginning of the year. Some things were said about being the right or wrong decision and that it was a mistake. The team and I have constantly proved everyone wrong, race by race."The tarmac temperature hit 50C at the Hungaroring but conditions are often wet in Spa, where Hamilton won in 2010. The seven-km circuit is the longest on the calendar and the most demanding and because of the track's vast area different microclimates mean it can be raining on one part, sunny at another. Corners such as Eau Rouge and Blanchimont push drivers and tyres to the limit.FEELING POSITIVEHamilton said: "Spa is a fantastic circuit and it's so much fun to drive. We're all looking forward to the second half of the season and the opportunity to bring home some more good results."Tyres have been a factor all season, with Pirelli under huge pressure to make them more reliable after races were marred by tyres shredding and even exploding, leading to a boycott threat from drivers. Given the incident-free 2013 Hungarian GP, rivals should now be able to focus purely on catching Vettel.Vettel is in a position similar to that of Hamilton in 2012. He headed for Belgium trying to figure out how to make up a 42-point deficit on overall leader Fernando Alonso. Ferrari was Red Bull's expected main rival for 2013 but Mercedes is now ahead in the Constructors' championship and Hamilton is only nine points behind Alonso, who slipped to third behind Kimi Raikkonen after a disappointing Hungarian GP."We're second in the Constructors' championship, a huge boost," Hamilton said. "We never would have thought we'd be in such a competitive position, still within shooting distance of both championships."'WE CAN DO IT'Alonso, since winning the 2013 Spanish GP in front of his home fans on May 12, has managed only two podiums. He was fifth in Hungary and he has not qualified higher than third all season, leaving him too much to do on race day. Off-track, he earned a public rebuke from Ferrari for comments he made alluding to needing a better car.Along with Alonso's current malaise, other issues behind the scenes will develop in the coming days and weeks. Raikkonen's future with Lotus is unclear and the Finn himself has been linked with a move to Ferrari. With five second-places to add to his win at the 2013 Australian GP, he must be wondering where he would be with a better car - closer than 38 points behind Vettel.Lotus team principal Eric Boullier said: "I would have to give Kimi 10 out of 10. He's done a terrific job right from the beginning of the season and his remarkable run of 27 consecutive points finishes speaks for itself. He's playing a big part in pushing the team forward."Ferrari team principal Stefano Domenicali called a meeting on Tuesday (Aug 20) to urge his team to focus only on the races ahead, not 2014. "We've spelled it out many times before," he said. "The driver topic is not a priority. If they have a winning car in their hands I am convinced they will know how to win with it. If we all believe, then we can do it."What seems certain is that Raikkonen will not drive alongside Vettel in 2014, with the spare Red Bull seat reportedly a certainty for Toro Rosso driver Daniel Ricciado. Red Bull is expected to confirm in Spa that the Australian will replace his countryman Mark Webber, leaving F1 at the end of the season to race sports cars for Porsche. Stay with Wheels24 for the 2013 Belgian GP weekend.