New York, Apr 6 : When American actress Lindsay Lohan made an impromptu appearance at Lily Allen's concert at the weekend, she even surprised the Brit singer herself.

Allen, 23, later recalled the incident to television host and comedian Jimmy Kimmel.

"That was a complete surprise," the New York Daily News quoted Allen as saying.

Lohan, 22, had walked up to Allen during her performance of Britney Spears' `Womanizer', given her a hug, and briefly shook her hips.

The `Mean Girls' star looked out of place, and after singing a few words with Allen, she stood awkwardly to the side before eventually walking off. (ANI)