Rihanna may be mourning her grandmother, but it was as though she channeled her grief into a spellbinding performance at the Barclaycard Wireless Festival in the U.K., delivering a medley of hits and closing Sunday night's show on July 8. The weather was not cooperating, at all, as rain fell from the skies, but most attendees stayed to enjoy RiRi while sopping wet.

"Thanks for staying to watch me in the rain ... Only in London would you guys stay to watch this show," the Bajan beauty, wearing her hair dark and natural, said, per Ace Showbiz.

Reportedly, the first-ever female headliner for this fest was Pink in 2010 and RiRi took the "female topliner" baton and ran with it, turning in a greatest hits set, including 'You Da One' along with a medley of 'Only Girl (In the World), 'Disturbia' and 'S&M.' She proved that ladies belong at the top of this fest, for sure.

When she performed her huge 'Talk That Talk' smash 'We Found Love,' the crowd was right there with here, singing along, just as loud as she was. There was an exchange of love and electric energy between RiRi and her adoring fans.

Jessie J was also a strong female presence, saying, "I was here five years ago in the audience watching Jay-Z. And now I'm up here, supporting one of my favourite artists Rihanna." Times have changed, for the better for Jessie J.

Rita Ora was also another female who rocked it on the second day of the three day festival, encouraging fans not to stay away despite the rain!

Other standouts were Drake, who headlined on Saturday, July 7, calling London "a second home" to him. When he performed 'Take Care,' RiRi didn't come out and perform with him; her vocals were patched in via sample. It garnered a huge singalong. He also incorporated pyro effects and of course a surprise cameo from his Twitter "wife" Nicki Minaj.

Deadmau5 closed out Friday night (July 6), twiddling his knobs, with an assist from Sofie.

While there was some fine talent spread over three days, it was RiRi's set that got the lion's share of attention. Rawr!

Watch Rihanna Perform 'We Found Love'

Watch Rihanna Perform 'Where Have You Been'

Watch Rihanna Perform 'Take a Bow' + 'Cheers (I'll Drink to That)'

Watch Rihanna Perform 'Don't Stop the Music'