A ‘Wicked’ reunion: Cynthia Erivo joins Ariana Grande onstage in London

Ariana Grande defied fans’ expectations Sunday night, when she brought out her Wicked co-star Cynthia Erivo during her concert at London’s O2 arena.

Ari is in the middle of her 10-show series at the venue, and the shows mark her first performances in that city in seven years. During Sunday’s show — the second in the series — Ari and Cynthia, both dressed in white, sang “For Good,” as well as the mashup of “Get Happy/Happy Days Are Here Again” that they first performed on the Wicked TV special in November.

Ariana’s London shows wrap up Sept. 1, after which she plans to take a step back from the spotlight.

In May, Cynthia told Variety that her close relationship with Ari, which was on display for several years as part of the seemingly endless Wicked press tours, was no act.

“I think that people didn’t really believe that we were actually friends,” she said. “But that’s also because people don’t know me very well. If I’m a friend, then I’m a friend. If I’m not, then I’m not.”

According to Cynthia, she and Ariana still text nearly every day. She told Variety, “It’s very interesting, watching what people’s perception is versus what the reality actually is — lots of psychologists seated at home deciding who we were, what we were going through, what we were doing and why.”