Chris Martin has paid tribute to his wife Gwyneth Paltrow in an unusually candid admission on US daytime TV.

Appearing on CBS Sunday Morning, the Coldplay frontman confessed that Paltrow was his first serious relationship and that marrying her was "like winning the lottery."

The couple met at a Coldplay gig in 2002 and married a year later. Martin admitted his uneventful love life prior to that was "pretty unusual."

"It's a big leap?" he said, when probed by interviewer Anthony Mason about his swift marriage to the Hollywood star. "What, from being a loser, to going out with an Oscar winner? It's a giant leap — like winning the lottery."

The couple are notoriously private about their relationship and are rarely pictured out in public together.

Martin said their two children - Apple, seven, and Moses, five - gave him purpose.

"I like what it does, just the idea of having to work hard so your kids are OK," he said.

In an interview a few months ago, Paltrow admitted that "We have periods that aren't all rosy. I respect him as the father of my children."

Gwyneth Paltrow is 'lottery' wife