VIDEO: Amber Riley Dances in a 'Class of Her Own'; Advances to Finals on DWTS

It was the semi-finals round on ABC's DANCING WITH THE STARS! Former DWTS pro dancer Maks Chmerkovskiy returned to the ballroom but this time as a guest judge, and the couples had to perform two routines to completely different versions of the same song.

During rehearsal week, Amber Riley visited the doctor to make sure everything was okay with her knees. After receiving a clean bill of health the Glee star asserted, "Now that I know there isn't any permanent damage, I really have the eye of the tiger."

Their first dance of the night was a Jazz routine to Bruno Mars 'Locked Out of Heaven'

Following the dance, the usually verbose Len said simply, "Do it again.'

Said Bruno, "you're just incredible, that was totally fierce, constantly surprising, the sync was out of this world - your versatility is astonishing."

Carrie Ann added, "You are in a class of your own. If Einstein could dance I imagine that's how he would dance - it felt like a mathematical equation and you solved it!"

Agreed Maks, "it was like Bob Fosse but for now. It looks like it comes easy to you - great job!"

The couple received a 39 out of 40 in Round 1.

Amber and Derek danced the Viennese Waltz for Round 2 of the competition.

Said Len following the dance, "there was smoke on the floor but there was fire in the performance - I loved it

Agreed Bruno, "you dance like an angel - lovely."

Added Carrie Ann, "you are so special and it is the way you interpret the music and the movement."

The couple received a Perfect Score of 40 bringing their total for the night to 79 points. They will move on to the Finals next week.