K-pop girl group f(x) made their first appearance as an official four-member group at the 2015 London Korean Festival this past Sunday.

The performance comes after last Friday's announcement that member Sulli had officially left the group to pursue her acting ambitions. Sulli (Choi Jin Ri) had previously taken a hiatus from the group during their "Red Light" promotions last year.

The remaining four members performed “Red Light” as well as “Shake That Brass,” the popular solo track from the group's rapper Amber Liu, and had fans cheering them on.

Fans showed their support for the new four member group.

“Still going to be a fan of them no matter what,” wrote Eklecticism posted Monday to the Korean news website Allkpop. “Through thick and thin.”

Others felt that the group did better because Sulli left the group.

“I think they’ll do much better as four,” wrote Kawaii8 posted Monday as well. “They have a different air to them without Sulli. Definitely a sharper group.”

After f(x) released their “Red Light” album, Sulli has been focusing on her acting career.

“After much discussion, Sulli will be leaving the group and focusing on her acting and solo actives,” read a statement from SM Entertainment posted last Saturday to the news site Inquisitr. “We have decided to respect her wishes.”

f(x) will continue as a four member group and will continue to balance group and solo activities. Sulli will still remain a part of SM Entertainment and will work with her for her future activities.

f(x) debuted as a five member group under SM Entertainment in 2009. They have been known for their experimental style in music and fashion and were also the first K-pop group to perform at the SXSW festival in the US.

Their album, “Pink Tape,” was also the only K-pop album to be listed on Fuse TV’s ‘The 41 Best Albums of 2013’.