Gymnast Laurie Hernandez and country singer/actress Jana Kramer brought sexy to the ballroom on a "Dancing with the Stars" night devoted to Broadway "Showstoppers."

Although she's only 16, Olympian Hernandez took on a grown-up role as she did an Argentine tango to the cell block number from "Chicago." She and partner Val Chmerkovskiy got a perfect score of 40 for that, and later Monday night, also received 40 for their "team-up" challenge with Kramer and her pro Gleb Savchenko.

Viewers saw how during rehearsal, Chmerkovskiy leveled with the teen that they had an awkward challenge – she would have to be sexy for the routine.

Hernandez laughed to her pro, "Should we ask my mom first?"

After the show, the gymnast told FOX411 about the famous "Chicago" number concerning murderous women, "I was channeling my inner Velma."

Hernandez said her mother "thought it was awesome. Actually, I had showed her a little clip we had from practice and I was like, 'Mom, okay, this dance is like very sexy' and she watched and was like, 'Go out there, you give it your all. When are you going to be able to do anything like this ever again? I support you. Just go for it.' I was like, oh, okay."

Still, Hernandez admitted to reporters during the dance, "I had to make sure I didn't giggle 'cause I have a habit if I do something right, then I giggle right after."

Meanwhile, Kramer, who has revealed her dark romantic history during the show, was horrified when Savchenko injured his knee during rehearsal. Although it looked like he might not be able to compete on Monday night due to the knee inflammation, and pro Alan Bersten worked with Kramer in practice, Savchenko powered through on show night.

Kramer garnered two perfect 40s-- for her sizzling "Waitress" themed waltz and "team-up" dance with Hernandez.

The singer told reporters backstage, "We only rehearsed for two hours together total so the fact that we were able to come together and be a perfect team, I think it just shows how close we are in our friendship…Gleb is still in so much pain but he was able to come out there and just dance for us and he didn't let me down."

Savchenko said, "I had a great doctor and he brought me back in no time" and he expects he'll be able to continue on the show with Kramer.

But more doubt remains for Indy car driver James Hinchcliffe, whose partner Sharna Burgess had to sit out a second straight week with a knee injury. Pro Jenna Johnson filled in again with Hinchcliffe and they received 36 points for their jazz routine based on the Broadway musical, "The Wiz."

In the "team-up" challenge, Hinchcliffe and former football player Calvin Johnson, Jr. scored 37 for a sheriff/outlaw paso doble.

Although Burgess' doctor had cleared her to dance, he warned her she could be risking more serious injury, so she decided to give the injury more time to heal.

Burgess said afterwards, "It was a last minute decision we made today on whether I was going to dance or not so that's really a lot of pressure on James."

Hinchcliffe made a small mistake in his individual dance, but was happy with his score. "I was able to bounce back from a problem halfway through and still finish the routine with the energy that I needed to," he noted.

Burgess said about her status, "I just have to take it day by day and continue to make the right decision for my career. But it's really difficult because I love every single thing about this season with James…and I don't want to miss any of it."

"Little Women LA" star Terra Jole and her partner Sasha Farber excelled with a Charleston to "Sweet Charity" for a score of 38. Later, they took 36 with Marilu Henner in the jazz "team-up." (On Monday, Henner was eliminated from the show).

As a joke, Jole landed right on top of Farber as he lay on the floor at the end of their individual dance.

The reality star, who has been dancing with a hernia, told FOX411, "I am wearing a brace…The hardest thing are actually the lifts, which, we had three of them…I'm being as safe as possible."

Johnson Jr. and partner Lindsay Arnold did a waltz to "Memory" from the Broadway hit "Cats" and earned 37 points. With Hinchcliffe, he got 37 points for a paso doble "team-up" dance.

Johnson told reporters their trip to New York to get instruction from the "Cats" crew on the Great White Way was a pleasure. "It was awesome to go behind the scenes to get into character."