Hines Ward and Kym Johnson impressed the judges on performance night. (Adam Taylor/ABC)

There’s just four celebs left now and inter-couple tensions are on the boil.

For this episode, the workload is high. It’s the semi-finals, which means two new routines and then a winner-take-all cha-cha for 15 bonus points.

Prior to each number, we’re treated some behind-the-scenes footage that’s cut to show the perilous physical and mental edge that “Dancing With the Stars” contestants must walk if they hope to cut the mustard.

Macchio goes first. His leg is still sore from and injury back in episode 8, but it’s his posterior that he really has to worry about. His partner, Karina Smirnoff, says it isn’t big enough. She prescribes a booty-reinforced undergarment.

For round one, they dance an Argentine tango. Macchio looks tense. He chases Smirnoff around a lamppost a couple times. The judges aren’t buying it, but they’re feeling merciful. He gets 25 points. 

Kirstie Alley goes next. Apparently, her and pro-dance partner Maksim Chmerkovskiy are having some sour moments during rehearsal. It’s all tears, sniping, and more tears. “There is no fear,” he says, trying to soothe her performance anxiety. But Maks’ new age admonitions are all for naught. Alley lets forth a tyrannosaurus rex squeal and bolts from the room. 

Somehow, they make it to the studio and dance a Viennese waltz. Sparks fail to fly. Alley and Chmerkovskiy look like a couple of nervous tweens forced to box step at cotillion class. Fortunately for them, the judges have their feel-good blinders on. “You do something that’s really magical,” Carrie Ann Inaba tells Alley. “You bring us into the full performance.” It’s nines all around, for 27 points.

For their intro, Chelsea Kane and Mark Ballas feign some mid-rehearsal dust-ups, but it’s all crocodile tears. They’re clearly aware that they’re enormously attractive and awesome at dancing, and they can’t hide it.

They do the Argentine Tango, too. The judges have mixed feelings. “I found that to not be up to par,” says Inaba. Tears well up in Kane’s eyes. Tonioli comes to the rescue, calling the performance sexy and comparing Kane to Sharon Stone. They walk away with 28 points.

Enough squabbling, time for some high-drama. Hines Ward’s partner, Kym Johnson, takes a nasty fall during practice. Cue the ambulance, the neck brace, and some footage of Ward gently mopping the sweat from her brow. But, come showtime, she’s ready to trip the light fantastic once more.

Another Argentine tango. The judges bask in the lustiness of it all. “It was like something from the ‘Kama Sutra’,” says Goodman. “It was like good sex. You never want it to end,” says Tonioli keeping the bodice-ripping ball in the air. Johnson and Hines weep with joy. Even Inaba manages to gin up some tears. It’s a perfect performance, 30 points.

Round two: time to roll out the baby pictures, biographies, and family testimonials. Alley isn’t afraid to take things to the dark place. “That’s when I started doing drugs, a lot of cocaine,” she says, airing out her lost years. Growing up, Hines Ward got a lot of support from his mom, a Korean immigrant. But when he told her he was going to be on “DWTS,” she laughed at him. Fortunately, he didn’t take it too hard.

And now, time to dance.

The padded pants can’t save Macchio’s ’70s kitsch-laden salsa routine. It’s a smack down, just 23 points. Chmerkovskiy and Alley score straight nines with a paso doble set to Cream’s “White Room.” Kane and Ballas bare “NYPD Blue”-level skin, dance a rumba, and fetch a perfect score. Ditto Hines and Johnson, who do a salsa.

The judges have been doling out the praise all night, but none of it has come Macchio’s way. He’s taken a real beating. The winner-take-all cha-cha gives him a shot at redemption, provided he can show up, “Karate Kid”-style, with the last-minute moves.

Sadly, it’s just not his night. Ward wipes him out.

Alley goes up against Kane and the judges pretend like it’s a hard call – that Alley is athletic and sensual and, no, nothing at all like a sack of laundry tumbling across the deck of the Titanic. Reason prevails and they cast a unanimous vote for Kane.

Then it’s Ward vs. Kane for the final cha-cha-off. You’ve got to hand it to Ward, he’s bulky — sometimes, when he moves his legs, he looks like he’s trying to work the clutch a new car — but he gives it all he’s got. It’s not enough, though. Kane and Ballas wind up with the extra 15 points.

The final scores:

Chelsea/Mark: 73

Hines & Kym: 60

Kirstie & Maks: 54

Ralph &Karina: 48

Photo Gallery: “Dancing With the Stars”

Last week’s results: Viewers save Macchio, toss Romeo

Last week’s performances: Insta-dance returns!