Given the mixture of disciplines and the numerous ways a fight can be lost in the UFC, the margin for error is as thin as it gets in all of combat sports. 

The fact that each mixed martial artist competes in four-ounce gloves doesn't help matters either, often producing a thunderous mixture of highlight-reel knockouts by year's end, not just from punches, but elbows, knees and kicks. 

Looking back on 2017, there were a number of one-strike finishes that fit the bill. Let's take a closer look at the best in show, as voted on by our CBS Sports panel. 

1. Francis Ngannou KO1 Alistair Overeem (UFC 218) -- Dec. 2 at Little Caesars Arena in Detroit

In a word: Scary. Ngannou, a chiseled, 6-foot-5 knockout machine, entered the bout on the verge of a title shot after finishing all five of his UFC opponents since his 2015 debut. But none of the knockouts produced by the native of Cameroon were as terrifying or devastating as the one-punch sleeper he landed on Overeem. 

Ngannou, who secured a shot at Stipe Miocic's title in January at UFC 220 with the victory, uncorked a left hand early in Round 1 from below his waist that appeared as if it might take Overeem's head clean off. The half hook/uppercut landed square on the chin and violently snapped Overeem's head back. This is about as ferocious as a one-punch knockout gets at the elite level as "The Predator" continued to announce himself as, quite possibly, the baddest man on the planet in waiting. 

2. Mike Perry KO2 Jake Ellenberger (UFC Nashville) -- April 22 at Bridgestone Arena

Ellenberger, a struggling welterweight, entered the fight badly in need of a win having lost six of his previous eight bouts. Unfortunately for the veteran of 19 UFC fights, Perry would offer no mercy whatsoever. Despite bleeding from his nose and mouth, Perry went on the attack in Round 2 with a series of knees from the clinch. But as the two separated in the center of the cage, Perry uncorked a savage standing elbow, which caught Ellenberger flush in the face and dropped him in sections onto the ground. Ellenberger was knocked cold and the fight was instantly called as Perry flexed for the crowd before showing off his break dancing moves. 

3. Marlon Moraes KO1 Aljamain Sterling (UFC Fresno) -- Dec. 9 at Save Mart Center

After dropping Sterling with a left hook early in the opening round, Moraes moved in to attack on the ground. But the former World Series of Fighting bantamweight champion briefly found himself trapped in an armbar for his efforts and was forced to scramble to his feet. Once Sterling stood up to join him, Moraes uncorked a chilling left knee to the face just as Sterling bent forward to attempt a takedown. Not only did the strike knock Sterling cold, causing him to fall on to his face, the impact threw his arms up in the air, appearing as if he was dabbing (which created a storm of memes on social media). 

4. Volkan Oezdemir KO1 Jimi Manuwa (UFC 214) -- July 29 at Staples Center in Los Angeles

Oezdemir, the hard-hitting light heavyweight from Switzerland, stayed true to his nickname of "No Time" by finishing his final two opponents in 2017 via knockout in a combined total of 70 seconds. The most recent finish against Manuwa was enough to secure Oezdemir a shot at Daniel Cormier's 205-pound championship at UFC 220 on Jan. 20. It was also enough to scare anyone willing to face him as Oezdemir, who needed just 42 seconds to dispose of Manuwa, broke free from an early clinch along the cage to buckle his opponent with an uppercut before following up three punishing blows. Oezdemir then pushed Manuwa down hard onto his back and scored three more times with hammer shots to force the stoppage. Manuwa was knocked loopy enough that he began to grapple with the referee as Oezdemir celebrated by pointing to an imaginary watch on his wrist. 

5. Ovince Saint Preux KO3 Corey Anderson (UFC 217) -- Nov. 4 at Madison Square Garden in New York

As far as knockout kicks to the side of the head are concerned, this was a particularly nasty one for Saint Preux, who has been no stranger to producing highlight-reel quality finishes throughout his up-and-down career. The former interim light heavyweight title challenger caught Anderson with his left leg to the side of the head, turning his chin inward at an awkward direction and removing him from his senses. The fact that OSP was down on the scorecards at the time and appearing on his way to a disappointing loss only made the win sweeter as it set the stage for a trio of dramatic finishes in title fights to close the card later in the night. 

Honorable mentions: Matt Brown KO1 Diego Sanchez, Holly Holm KO3 Bethe Correia, Edson Barboza KO2 Beneil Dariush, Julian Marquez KO1 Phil Hawes, Alexander Gustafsson KO5 Glover Teixeira, Jon Jones KO3 Daniel Cormier, John Moraga KO1 Magomedov Bibulatov, Galore Bofando KO1 Charlie Ward, Derrick Lewis TKO2 Travis Browne, Darren Elkins TKO3 Mirsad Bektic, TJ Dillashaw TKO2 Cody Garbrandt, Rose Namajunas TKO1 Joanna Jedrzejczyk.