After the double elimination round which sent Chris Soules and Robert Herjavec last week, the competition is down to the final four on 'Dancing With the Stars. This week, Nastia Liukin, Rumer Willis, Noah Galloway, and Riker Lynch were on their A-game as they danced two routines for the semi-finals round, and one of the routines saw them paired off with one of the judges for the first ever Judges Choice round which gave the judges control of the dance.

The semifinals featured six perfect scores and a lot of emotional moments for the contestants and the audience, as one of the stars proposed to his girlfriend on the show, and Len Goodman made his return to the dance floor.

Here's how they fared on the semifinals of 'Dancing With the Stars':

Rumer Willis and Valentin Chmerkovskiy
First Dance: Viennese Waltz
Judge's Choice: Contemporary coached by Bruno Tonioli
Scores: First dance, 38 (out of 40); Judge's choice, 30 (out of 30)

Rumer's video package featured her family members talking about how she overcame her insecurities and how much she's grown since she's been on the show. For their first dance, Rumer and Val took to the dance floor for a 'Fifty Shades of Grey' inspired Viennese Waltz. "Another great dance, well done," said Len. "You were the perfect Anastasia," said Julianne Hough.

For their second dance, the pair was coached by Bruno Tonioli for a 'Swan Lake' themed contemporary number. "If I had my own private leader board, you are my highest marker," said Len.

Noah Galloway and Sharna Burgess
First Dance: Viennese Waltz
Judge's Choice: Paso Doble coached by Carrie Ann Inaba
Scores: First dance, 36; Judge's choice, 30

Noah's video package focused on how he returned home from the war and how he was able to rebuild his life after he lost his arm and leg. For their first dance, Noah and Sharna earned rave reviews for their Viennese Waltz, and while talking to Erin Andrews, the army vet was joined by his girlfriend Jamie.

"This song, 'The Time of My Life', you gave that to me," he said to Jamie, "and you know, I've got to do this here," he said as he dropped down to one knee. "Will you marry me?" As Jamie said yes, the audience and the judges got on their feet, and there wasn't a dry eye in the studio.

For their second dance, Sharna and Noah were coached by Carrie Ann, and their Paso Doble told of Noah's injury and recovery. "To me, that was one of the best dances I've ever seen you do," said Len.

Riker Lynch and Allison Holker
First Dance: Contemporary
Judge's Choice: Argentine Tango coached by Julianne Hough
Scores: First Dance, 40; Judge's Choice, 30

Riker's video package focused on his relationship with his family, particularly with his siblings who regarded him as their leader. For their first dance, Allison pushed him out of his comfort zone with an emotional and powerful contemporary number which had Bruno gushing, "I really hope you make it into the finals, it wouldn't be the same without you." Julianne praised Riker's skill as she said, "I could not tell who was the pro in that dance."

For their second dance, Julianne coached and danced with the two for their Argentine Tango. "You are a leading man, up there with the best!" cheered Bruno. "You dance like a champion!" said Carrie Ann.

Nastia Liukin and Derek Hough/ Sasha Farber
First Dance: Quickstep
Judge's Choice: Viennese Waltz coached by Len Goodman
Scores: First Dance, 40; Judge's Choice, 30

Nastia danced with Sasha for the first dance because Derek couldn't dance the Quickstep due to his ankle injury, nevertheless the Olympic gold gymnast was praised by the judges as Julianne told her, "You are now a dancer, you're not just a gymnast!"

For their second dance, Len chose the Viennese Waltz for them which enabled Derek to dance with his partner. The routine was also a bittersweet one for Len as he said, "For everyone, there comes a time when you can no longer do something. But you always think back to how it was…Sometimes I get that feeling and I think, 'Gee I wish I could still dance like that.'"

Their waltz showcased a connection between Derek and Nastia, and towards the end, Len took to the dancefloor to dance with Nastia. Everyone was in tears, particularly the judges as Carrie Ann choked out, "Tonight, that was something so spectacular. That was a moment that I will remember forever. Bruno said that the performance "glowed with a nostalgic warmth and love."

Which three pairs will be competing for the Mirror Ball Trophy? Watch the elimination night of 'Dancing With the Stars on Tuesday, May 12 at 8pm on ABC to find out who will be eliminated and who will go on to the grand finals next week.