The 1976 Olympic gold medal winning figure skater and Tristan became the first couple eliminated from the competition, ultimately saving either The Real Housewives of Beverly Hills star Lisa Vanderpump and partner Gleb Savchenko or boxer Victor Ortiz and partner Lindsay Arnold.
Before Dorothy revealed her bad news, Lisa and Victor and their partners were declared the bottom-two couples and in danger of elimination based on the combination of theDancing with the Stars judges' scores they had received during the last two weeks of Monday night performance shows and the home viewer votes that were cast afterwards.
"I have taken the advice of my spine surgeon and I need to withdraw from the competition. I have an injury that could be irreparable and nerve damage, and it would be completely unfair for me to stay in this and have any of these people go home," Dorothy explained at the end of last night's broadcast.
"I can't do what I need to and the rest of life [being] physical as an athlete is important. I can't do [Tristan] justice and these are the most amazing people who want to be here. And it's not that I don't want to be here, but I wish that I could give it my all and I can't."
"Well I mean, it's a decision that has to be made, you know?" Tristan added. "I'm certainly not frustrated at her; I'm frustrated 'with' her. That's the important thing all the time -- there's something a lot bigger going on than this competition, as great as it is, you know what I mean?"
"It's been a wonderful ride," Dorothy continued.
"I wish I could stay but I can't do justice to the commitment, and hopefully I'll have 30 years where I can really learn how to dance and come back! Doctors' orders, thank you. I'm going to miss you all, and this man [Tristan], is just a treasure. He's just been so supportive. And all of these people -- it's just an incredible place to be and I just feel so lucky that I was a part of it for a short time."
"I want to mention because you were so good about telling us this during the last few minutes here, a couple who would've gone home tonight gets a one-week reprieve. Use it well, use it well!" Tom noted.
Victor and Lindsay -- who competed on So You Think You Can Dance last summer -- and Lisa and Gleb both performed jive routines that received 18 out of 30 possible points during Monday night's performance show. Dorothy and Tristan also danced a jive routine, but it earned only 15 points from the judges.
The other couple who tied with the three pairs for eighth place was country singer Wynonna Judd and partner Tony Dovolani, who performed a quickstep routine that received 18 points.
Disney Channel star Zendaya Coleman and partner Val Chmerkovskiy finished in first place on the Dancing with the Stars' combined two-week leaderboard with 50 total points. Zendaya and Val performed a jive which received 26 points from the judges during Monday night's show.
Former American Idolfinalist and country singer Kellie Pickler and partner Derek Hough finished in second place on the leaderboard with 47 total points after they performed a jazz routine which received 26 points.
Third place on the two-week leaderboard went to 2012 Olympic gold medal winning gymnast Alexandra "Aly" Raisman and partner Mark Ballas who walked away from the night with 45 points after they earned 24 points from the judges for their quickstep routine.
NFL football player Jacoby Jones and partner Karina Smirnoff landed in fourth place with 43 points following their jazz dance which received 23 points on Monday night.
Soap star Ingo Rademacher and partner Kym Johnson came in fifth place on the leaderboard with a combined 40 points. On Monday night, they danced the quickstep and racked in 20 points from the judges -- the same score they had received last week for their contemporary routine.
The Bachelor star Sean Lowe and partner Peta Murgatroyd finished in sixth place on the judges' two-week leaderboard with 39 points after they performed a jive routine which received 20 points.
Seventh place went to actor and comedian Andy Dick and partner Sharna Burgess, who added 20 points to last week's score for their jazz routine, giving them 37 total points.
Actor and comedian D.L. Hughley and partner Cheryl Burke finished in twelfth -- and last -- place at the bottom of the two-week leaderboard with 28 points after they danced a quickstep routine that earned only 16 points from the judges during Monday night's episode.
The 11 remaining sixteenth-season Dancing with the Stars couples will return for another two-hour performance show on Monday, April 1, after which the judges' scoring and home viewer voting results will be combined and one couple will be eliminated on the season's second results show on Tuesday, April 2.