Rare overall win for Britain's Cavendish in Qatar By Gilles Le Roc'h DOHA (Reuters) - Former road race world champion Mark Cavendish won his fourth straight stage of the Tour of Qatar on Friday to wrap up a rare overall victory in his second race for Belgian outfit Omega Pharma-Quick Step. The 2011 world champion, who has 23 Tour de France stage wins to his name, clinched another sprint finish in the sixth and final stage in the Qatar capital to show he is enjoying life with his new team, having left Britain's Team Sky last year. Cavendish, who has few overall triumphs given that he is an out-and-out sprinter, started his Omega Pharma career at the Tour of San Luis in Argentina with one stage victory and he has been showering his team mates with praise all week in Qatar. Sat behind @opqscyclingteam from start to end & the sense of pride I felt, as they rode & rode, can't be described. Another win. Thanks guys," Cavendish said on his Twitter account after Thursday's stage win. Cavendish, 27, was little more than a domestique in 2012 at Sky, who put all their efforts into securing a first British win at the Tour de France when Bradley Wiggins topped the podium ahead of compatriot Chris Froome. Writing by Tom Pilcher in London, Editing by Clare Fallon