WATCH: Justin Bieber, The Wanted Perform On 'The Voice'

NBC's The Voice continued its overly complicated quarterfinals elimination process on Tuesday, but made up for the head-scratching confusion with sensational appearances by boy band The Wanted and Justin Bieber (who inadvertently went up against gilfriend Selena Gomez, who performed on the elimination round of ABC's Dancing with the Stars).

Aided by Team Blake, as well as fog, fireworks and fiery female backup dancers, The Wanted kicked things off with their song, "Chasing the Sun." That was followed by much ado about Christina Aguilera's "controversial" sudden elimination of Jesse Campbell on Monday. Basically, many were shocked and surprised, but Aguilera is sticking to her guns and moving on.

Then, more updates on Team Christina: opera singer Chris Mann was saved by America's votes, leaving Lindsey Pavao and Ashley De La Rosa to sing for the remaining spot. America also saved Jermaine Paul from Team Blake, sending him on to the semifinals. That meant Erin Willett and RaeLynn would have to sing for their lives.

First up in the sing-off round was Ashley, singing Lady Gaga's mermaid hit "You and I." Judge Adam Levine said the performance wasn't his favorite, though he thought she should stick around. Then it was Lindsey's turn to sing "Please Don't Go" instead of Monday's song, Katy Perry's "Part of Me." Judge Cee Lo Green called the performance "wonderful" and praised Lindsey's "charm."

Enter Bieber, who introduced his "Boyfriend" — the video, that is. Not the whole video, just a clip. But it was hands-down the most exciting part of the show. Then host Carson Daly invited Bieber to perform "Boyfriend" on The Voice in three weeks. Bieber's album, Believe, comes out June 19, by the way.

Then it was time for a teary-eyed Aguilera to save one from her team, and she chose Lindsey, effectively sending Ashley home. Following the elimination, Erin from Team Blake did Creedence Clearwater's "Rollin' on the River" à la Ike & Tina Turner, while RaeLynn performed a twangy-er version of The Band Perry's mega-hit, "If I Die Young."

Blake decided not to go with his country music companion, choosing to save Erin over RaeLynn.

Watch the entire episode here: