MANAMA Defending triple world champion Sebastian Vettel extended his lead in this year's title race on Sunday when he claimed an impressive victory for Red Bull in an incident-filled Bahrain Grand Prix. The race finished without any disruption amid tight security and despite earlier clashes between police and Shiite protesters in villages in the Gulf kingdom.It was 25-year-old Vettel's second win in four races this year and the 28th of his career as he repeated his victory of 2012. The German's victory saw him move into sixth on the all-time list of Grand Prix wins taking him past Jackie Stewart. Starting second, Vettel took the lead on lap three and then controlled the 57-laps race as he came home 9.1 seconds clear of nearest rival Finn Kimi Raikkonen of Lotus. "It was a fantastic race," said Vettel. "I have to give a big, big thank you to the team today it was faultless from start to finish. The pace was phenomenal the car was great. We took good care of the tyres and it all paid off."  Frenchman Romain Grosjean finished third in the second Lotus, as the Renault powered team made the best of excellent tyre conservation. It was the same first three as last year's race.Grosjean denied fourth placed Briton Paul di Resta of Force India his first ever podium finish. Briton Lewis Hamilton, the 2008 champion, fought hard to finish fifth for Mercedes after a late battle with Australian Mark Webber who came home seventh in the second Red Bull, Mexican Sergio Perez smashing his way to sixth for McLaren. Two time champion Spaniard Fernando Alonso, who lost the use of his DRS on his Ferrari, came in eighth ahead of pole starting Finn Keke Rosberg in the second McLaren.Like many, Rosberg struggled with serious rear tyre wear. Briton Jenson Button finished 10th for McLaren after several clashes with his own team-mate Perez. On a sizzling hot day at Sakhir, Rosberg made a clean start to lead, but struggled to pull clear of the scrap behind him as Vettel and Alonso swapped places in second and third before, on lap three, the champion surged into the lead with a classic pass on the Finn.Knowing he had to push early, Vettel reeled off a fastest lap on lap four as Alonso chased him ahead of a defiant Rosberg who, in turn, was struggling with his rear tyres to stay ahead of a rampant Di Resta. Alonso became the first of the leaders to pit as the Drag Reduction System (DRS) was stuck on his Ferrari and he required two stops. This left Vettel out in front until lap 11 when he led Massa in for new tyres, one lap after both Rosberg and Button had done the same, all of which meant Di Resta led the race ahead of Raikkonen. The Scot remained out in front until lap 15 when he also pitted and Raikkonen took over, but the Finn was unable to resist the chasing Vettel on the same lap and the Red Bull swept through on the inside to lead again. Vettel was soon more than two seconds clear while, behind him, several drivers were struggling with disintegrating tyres and punctures as the heat, dust and debris took their toll. By lap 17, when Raikkonen pitted, Vettel had his Red Bull team-mate Webber for company in second place until lap 22 when the Australian pitted leaving the German ahead of the field by 22 seconds.This enabled him to pit again and rejoin in the lead while his main title rivals were slithering and blistering in pursuit. Alonso, having pitted again on lap 24, was 13th and racing without DRS while Raikkonen and Hamilton were also struggling to keep pace. By mid-distance, it was clear that the McLaren men were ready to race one another as Button, having fought to pass Perez for sixth, had to drive him off the track to defend fifth just five laps later when the Mexican attempted to pass. "Come on guys," Button moaned on the team radio. Vettel, however, remained supreme, leading at his own pace by 27 seconds, with 16 laps remaining - as he demonstrated again why he is the dominant driver of his time.