Kane West also out sold 50 Cent in the UK Charts

West's Graduation shifted 957,000 copies in its first week of sales while 50 Cent's album, Curtis, only sold 691,000, according to Billboard.

Before the albums went on sale 50 Cent vowed he would retire from making solo albums if he was outsold by West.

He has now axed his European tour and a performance at London Mobo Awards.

'Historic moment'

Speaking to the Associated Press, West said: "It feels overwhelming. Everyone is coming up to me and telling me how proud they are of me."

"To be a champion, you've got to take out a champion," he added.

50 Cent, who is planning a world tour for his album, said: "I am very excited to have participated in one of the biggest album release weeks in the last two years.

"Collectively, we have sold hundreds of thousands of units in our debut week. This marks a great moment for hip-hop music, one that will go down in history."

To be a champion, you've got to take out a champion Kanye West

Earlier this week his spokeswoman said "unforeseen circumstances" had led to the temporary postponement of his tour, but refused to comment on any retirement plans.

The rapper was also due to perform at the Vodafone Live Music Awards in London, as well as at an MTV show in Germany on Friday. Those appearances have also been scrapped.

On Sunday it was announced that West had also beaten 50 Cent in the UK album charts.

West and 50 Cent, whose real name is Curtis Jackson, both released their third albums last week.

50 Cent threw down the gauntlet last month in an interview with hip-hop website SOHH.com.

"If Kanye West sells more records than 50 Cent on September 11, I'll no longer write music," he said.

"I'll write music and work with my other artists, but I won't put out any more solo albums."