A mere two days after attending her grandmother's funeral in New York City, Rihanna returned to the stage last night (July 8) at London's Wireless Festival, Contact Music reports.

The singer had previously cancelled her appearance at the Rock in Rio fest in Madrid, Spain, and as she continued to mourn the loss of Clara "Dolly" Braithwaite -- an important figure in Ri's life -- fans worried she would pull out of the Hyde Park gig.

Instead, she braved stormy conditions to play a hits-packed set, according to the NME.

"Only in London would you guys stay in the rain," she told fans, according to the music site.

The clouds apparently parted just prior to her performance of "Umbrella," and afterward the Bajan songstress took to Twitter to give thanks to her British supporters.

"#wireless I'm still bugging about how awesome the UK waz 2'nt," she tweeted.

See Photos of Rihanna's Harper's Bazaar Cover Story

%VIRTUAL-MultiGallery-159847|159709|159566|159089%

Watch Rihanna's "You Da One" Video