He quit the race, abandoning his waiting wife, and carried on to the Cape of Good Hope for a second time.

ECONOMIST: The hubris of racers today

But on Thursday Armstrong crashed, cutting himself badly, and quit the race.

FORBES: Can Landis Wreck Lance's Brand?

But their support was spread among a fractured GOP field, and their main standard-bearer, former Massachusetts Gov. Mitt Romney, quit the race after a disappointing showing in February's Super Tuesday primaries.

CNN: McCain wins GOP nomination; Huckabee bows out

The lack of a strong alternative was the main reason Mr Giuliani was not forced to quit the race as soon as the media publicised his affair with Judith Nathan, a wealthy divorcee.

ECONOMIST: The New York Senate race

Should Akin quit the race?

CNN: Akin bows out of CNN appearance at the last minute

The son of a fishing trawler captain who quit school to race motorcycles, Bernie Ecclestone built his fortune from auto sales, property and the transformation of Formula 1 into one of the world's most popular sports.

WSJ: The Ecclestones: The New First Family of Real Estate

The millionaire novelist quit the mayoral race on Saturday after admitting he asked a friend to provide him with an alibi for a dinner date he thought would be raised in the sensational 1987 Monica Coghlan libel trial.

BBC: Hague blames Archer's lies

Last week, former President Carter urged Nader to quit this year's race.

CNN: Nader says he'll meet with Kerry

"The one way you can't win a race is to quit it, and until somebody beats me, I'm going to answer the bell for every round of this fight, " he said.

NPR: Solid Wins for McCain; Clinton, Obama Close

So when one of the titans quit the contest last Friday, all the gas went out of the race, right?

CNN: Rudy's soulful exit