Rihanna performed in Singapore recently. Cara Delevingne and Katy Perry's friend reportedly got high and lip-synced at the Grand Prix concert, prompting her fans to react negatively on Twitter.

According to Hollywood Life, Chris Brown's ex-girlfriend left fans disappointed after she was reportedly stoned and not able to sing every song at the F1 event on Sunday.

One fan, Jason Denning posted a message on Twitter with a few choice words for the singer.

"Rihanna must have been going for the world record of how little she can sing in her live performance at the Singapore fl concert #Rihanna," @JFVDenning tweeted.

Another fan, Levan Derwin Haikal tweeted about how RiRi looked bad onstage, according to HL.

"Rihanna looked ratchet as hell, she can't dance and I swear she looks drunk or high on some drugs on stage the whole time," @levandarwin posted.

The Bajan beauty, who has been romantically linked to Drake, A$AP Rocky and Justin Bieber, got a very cold reception from her fans. Rihanna has been outspoken in the past about loving marijuana, and has also had issues at her concerts with fans.

In July, some concertgoers threw food including potato chips at Rihanna after she showed up a hour late to a concert in Manchester. To read our first story on that event, click HERE.

Think Rihanna's fans were too hard on her or not? Let us know in the comments section below!