The race for the mirror-ball trophy heated up on Monday night's "Dancing with the Stars" as the five remaining couples battled to land one of the four places in next week's semi-final round. In order to qualify, each of the couples had to perform both a ballroom dance and a Latin dance, which was set in a specific decade.

Dancing first in the ballroom round were songstress Mya and her professional partner Dmitry Chaplin with the quickstep. Head judge Len Goodman teased them, saying, "My priority is how you dance. Your priority is the 'wow' factor. We got off with a sticky start with the Viennese Waltz on week one. I was a little disappointed tonight because I couldn't find anything to criticize!" Bruno Tonioli raved, "Ladies and Gentlemen, this is quality. This quickstep is like vintage champagne -- light, sparkling and full of flavor. After you taste it, nothing else will do." Carrie Ann Inaba enthused, "You made something so difficult and intricate look like it flowed out of your body." Mya and Dmitry wowed the judges into 29 out of 30 points.

Next up were Aaron Carter and Karina Smirnoff dancing the foxtrot. Bruno commented, "I can see how much work went into this. You tried to get the style right, but it was a little tense. It didn't have the ease of flow to sell the foxtrot, and it wasn't as smooth as it could have been." Carrie Ann agreed, pointing out, "We are going to watch you like hawks this week. I do agree with Bruno. You were going for every detail, but there was a loss of fluidity." Len said, "Watching you is like watching my son in a toy shop. There are so many emotions. I am proud of you no matter what happens. You tried so hard. The judges awarded them a disappointing 23 points.

Dancing third with the quickstep were Joanna Krupa and partner Derek Hough. Carrie Ann pointed out, "These routines are really long: a lot of content; a few out-of-sync [steps with Derek]. Your frame and character was nice. You forgot to point your toes." Len agreed, saying, "There was a lot of running about. This is not the standard for the quarter-finals." Bruno criticized, "It looked like you were running away from the scene of the crime. A difficult dance, you played it well, but downstairs there were a few issues. Not one of your best performances." The couple earned 23 points.

Kelly Osbourne and Louis van Amstel took to the ballroom floor with the foxtrot. Len told her, "It has been a long while since we've seen you do ballroom. You bring grace. Your posture was good. I liked the routine, but your footwork was a distraction." Bruno said, "Who would have known you could be so light and ethereal? When you keep your focus, it works. You sustained the performance. That is the way to go." Carrie Ann pointed out, "You have a secret weapon. The moment you have a breakthrough, the audience goes crazy for you, but if you are going to continue, you are going to need to work on your spots and your range of motion." Kelly and Louis were awarded 25 points.

Last, but not least, in the ballroom round were Donny Osmond and Kym Johnson dancing the Viennese Waltz. Bruno enthused, "You can really play it. It was like watching a Lifetime movie, emotional and romantic." Carrie Ann raved, "I found it mesmerizing. There was something special about that dance. This time, you didn't over-perform it." Len admitted that there was improvement in Donny's posture, and he complimented him on a difficult step, but he criticized the dance as being "a bit arty-farty." They received 26 points.

The fiery Latin round began with Mya and Dmitry pulling out all the stops with a '70s-themed samba. Carrie Ann raved, "I believe it! I believe that you want to win this competition. Your samba was beyond belief." Len agreed, adding, "You were absolutely on fire. Your hips were hypnotic. Tonight, you have produced two dances with the highest standards with no gimmicks." Bruno complimented, "You are unbelievable. You do a mean, mean samba." Mya and Dmitry earned the first perfect score of the season: 30 points.

Aaron and Karina returned with a '90s-style samba. Len admitted, "That was tough. We had just seen somebody come out and do a samba and be awarded a perfect score, and you had to follow it straightaway. You came out, performed it, you sold it, and you worked your socks off." Bruno told Aaron, "All that energy is made good [in this dance]. It was a success." Carrie Ann said, "I could only think of all the difficult times you have had. I was hard on you in the beginning. You are now a great performer. You have smoothed out the edges. You were hitting it." They earned 27 points.

Joanna and Derek flashed forward for a futuristic, robotic Paso Doble. Bruno complimented them, saying, "A masterful reinvention of a classic. Derek, you are a genius." Carrie Ann agreed, saying, "That was an outstanding execution of the theme. Derek, not only are you amazing, but Joanna you didn't miss a step. That was outstanding." Len said, "Bruno took my words. I wrote here: genius. I didn't know how you were going to [execute it], but not only was the theme great, the content of the Paso Doble was great." The praise was reflected in a score of 29 points.

Kelly and Louis jittered to a '60s-themed jive. Len said, "You have been an absolute revelation to me. I thought the pressure would get to you, but you come in week after week, stronger and stronger." Bruno joked, "Groovy, baby. That was jiving all the way down to Carnaby Street." Carrie Ann complimented, "Definitely one of your best performances. I love the way you came alive. You were in your comfort zone, but there were a few little missteps." The judges awarded them 26 points.

Donny and Kym wrapped up the night with an '80s-style, glam-rock Paso Doble. Len labeled it "the most crazy, bizarre Paso Doble that I have ever seen, but I liked it." Bruno said, "Donny, that had more camp in it than a drag queen's convention. No one could top this. It was like Donny doing Marie doing Donny." Carrie Ann told them, "I thought it was hysterical. I thought you did a great job on going back to that era. I think you may have stepped into insane." Despite the praise, the judges only gave them 24 points.

On Tuesday night's results show, airing on ABC at 9 p.m., multi-platinum Grammy Award-winning artist Michael Buble will perform "Haven't Met You Yet," the first single from his just-released Crazy Love CD. Then Susan Boyle takes to the "DWTS" stage for a show-stopping performance of "I Dreamed a Dream," a cover of the famed Les Misérables song, from her forthcoming debut album of the same name to be released on November 23.