Dario Franchitti has been handed the chance of a $30 million (about £14.8 million) contract to make him one of the richest British racing drivers in history after winning the prestigious IndyCar championship at a dramatic last-gasp final race of the season. The Scot went to the Chicago Speedway Indy 300 on Sunday for a head-to-head with Scott Dixon, with the winner set to take the championship.

But even a driver who is no stranger to drama could have forecast what was to come.

Dixon had the upper hand and led into the last lap with Franchitti trailing in second place. Suddenly, Dixon’s car lost power as he ran out of fuel and he was forced to watch helplessly as Franchitti swept by to take the chequered flag and the title.

It was a bizarre climax to Franchitti’s ten-year quest to be the IndyCar champion. He lost out in 1999 to a young Juan Pablo Montoya when they tied on points but the Colombian won on his greater number of victories. But Franchitti was racing under a black cloud that season, following the death of Greg Moore, his best friend in motor racing.

Even last year, Franchitti was on the verge of quitting to spend more time with Ashley Judd, his film star wife. But his decision to try one more season has paid dividends: he became only the fourth Briton to win the fabled Indianapolis 500 — after Jim Clark, Graham Hill and Dan Wheldon — and is only the third British IndyCars champion, following Nigel Mansell and Wheldon. He also scored a record number of championship points.

The victory means more riches for one of the highest-earning British sportsmen, even though he is little known at home. Apart from his $1 million championship prize money, he is being tempted to join the NASCAR series, the USA’s most popular form of motorsport. He says he needs a fortnight to consider his options but the estimated $30 million deal could tempt him, ironically, to follow Montoya, who left Formula One for NASCAR last year.