Pop star Phil Collins has cancelled two shows at the Royal Albert Hall after he slipped over in his hotel room.
Collins, 66, who has difficulty walking following back surgery, suffered a severe gash near his eye after falling on the way to the toilet.
His management said he had stitches in hospital for the cut, and will be kept under observation for 24 hours.
The shows were meant to take place on 8 and 9 June and have now been rescheduled for November.
As they were postponed just hours before Collins was due to perform, some fans were already travelling to London when they heard the news.
One fan wrote on Facebook: "Sorry to hear that ... but we are sat on a train on our way to see him. #gutted .... no idea what we are going to do now 😢."
Another, who was at Wednesday's gig, added: " Amazing night last night!!! What a fantastic fan base you have. Get well very soon xxxxxxxx."
His management's post on Facebook added that the singer hit his head on a chair when he fell in the middle of the night, but is "recovering well". He will be kept under observation for 24 hours.
The singer, whose condition is described as "drop foot", sent "sincere apologies and thanks to fans".
The post said he has had a "fantastic week at his first shows in 10 years, cannot thank people enough for their warm reaction and is excited to return".
All tickets for 8 June will be valid for 26 November and tickets for 9 June will be valid for 27 November.
Collins will continue his tour with his next date on Sunday in Cologne, followed by Paris, before returning to London for to headline BST Hyde Park on 30 June.
Oscar, Grammys, Brits and Globes
Collins, who also played with prog-rock band Genesis, is one of the most successful songwriters and performers of all time.
He is one of only three recording artists, alongside Paul McCartney and Michael Jackson, who have sold more than 100 million albums worldwide both as solo artists and as members of a band.
His number one singles include A Groovy Kind of Love and Against All Odds.
Collins has won seven Grammy Awards, six Brit Awards, an Oscar and two Golden Globes.