Warren (9-3) submitted Kirk via armbar in the second round of their bantamweight tournament semifinal, which took place Friday inside the Moda Center in Portland, Ore. Referee Jason Herzog stopped the bout at the 1:40 mark.
"I would get hurt or move out of the country," Warren said when asked whether he had a message for Marx. "When I get ahold of you, I'm going to crush you worse than I crushed [Kirk]."
It was Warren's first appearance since a unanimous decision over Owen Evinger last November. The bout was supposed to take place earlier this month at Bellator 98 but was postponed when Warren failed to receive medical clearance due to what he later called a doctor's error.
The layoff appeared to have little effect on his confidence, as Warren showcased his typical, often wild, aggressive style. He ate several hard counterpunches by Kirk early but continued pressing forward with flying knees and overhand rights.
A spinning back kick badly missed its target in the first round, but the same couldn't be said for Warren's takedown attempts. He slammed Kirk (10-3) to the mat on several occasions and finished the frame landing hard punches to the side of Kirk's head.
An early takedown in the following round was a bad sign for Kirk, who entered the bout a significant underdog. He fought off Warren's attempt to gain full crucifix but gave up his back in the ensuing scramble. Warren eventually worked into a modified armbar to set up the tap.
"I felt I was moving better," Warren said. "I felt under control. I wasn't rushing things."
A former Bellator champion at 145 pounds, Warren fell short in his first run at the bantamweight title when he was knocked out by Alexis Vila in a quarterfinal matchup in 2011. Kirk remains winless in the Bellator cage at 0-3.
Sarnavskiy makes quick work of Davis
Marcus Davis' night was pretty much over before it started.
Davis fell victim to a quick finish at the hands of Russian lightweight prospect Alexander "Tiger" Sarnavskiy, tapping to a rear naked choke at 1:40 of the first round.
It's the 17th time Sarnavskiy (24-1) has recorded a first-round finish.
Davis (22-10) came out circling away from Sarnavskiy's power but failed to get out of the way of a step-in, straight right hand. The strike dropped Davis to the mat, where he turtled up and quickly gave up his back.
That was all the opportunity Sarnavskiy needed. He sank Davis into a body triangle and peppered away with left hands until the neck was exposed. Once Davis complied, it was a wrap.
Sarnavskiy, 24, extends his current win streak to four. His only loss came via split decision to Rich Clementi at Bellator 77 last October. Davis suffered only the third submission loss of his 10-year career.
Tirloni advances to lightweight semifinals
Ricardo Tirloni's fourth bid at a Bellator tournament final is still alive.
Tirloni (16-4) defeated Rich Clementi via unanimous decision to advance to the Bellator lightweight tournament semifinals. Judges scored the contest 30-27, 30-27 and 30-26.
The Brazilian lightweight has fallen twice in the first round of a Bellator tournament and once in the second round. He was bounced from the most recent edition at 155 pounds by a unanimous decision loss to Will Brooks.
The fight looked more like a kickboxing match than a mixed martial arts bout through two rounds. Clementi (45-23-1) found a steady home for the inside leg kick and jab but refused for the most part to follow up with any type of combinations.
Tirloni opened an early cut on Clementi's forehead during an exchange. He targeted the cut with counter left hooks throughout the rest of the fight.
In the final round, Tirloni finally surprised Clementi with a takedown. He executed an outside trip along the fence, then landed a series of hammerfists as Clementi tried to get back to his feet.
Tirloni snaps a two-fight losing streak with the win. Clementi falls to 2-3 within the Bellator cage.
Brooks shines in victory over Alessio
Brooks (11-1) blew through Alessio in the opening round of the Bellator lightweight tournament, defeating the veteran via unanimous decision by scores of 30-27, 30-26 and 30-25.
"I'm just going to enjoy this victory," Brooks said. "John Alessio is a veteran. To be able to compete against him and get the W -- I'm going to enjoy this."
Alessio (34-17) fought back throughout the 15-minute affair but found little success regardless of which strategy he employed.
A hefty speed advantage for Brooks was visible early, as he terrorized Alessio's lead leg with inside kicks. He opened a cut near Alessio's left eye midway through the first round.
Alessio pulled guard in the second round, looking for a guillotine, but Brooks escaped fairly easily. Alessio pursued with punches on the feet, at one point dropping Brooks with a right, but it appeared that was more the result of Brooks getting his feet crossed than Alessio's strike.
With Alessio still pushing late in the fight, Brooks tagged him with a knee on his left cheek as he shot for a takedown. That was the icing on the cake for Brooks, as he finished out the round in top position with Alessio bleeding badly from a fresh cut.
Brooks is now 3-1 as a Bellator lightweight, with wins over Alessio, Tirloni and Cris Leyva. Alessio falls to 0-3 in his past four contests, with one no decision.
Awad submits Stapleton in first round
It's a good thing Saad Awad isn't paid by the hour. He'd be broke.
Awad (15-5) advanced to the Bellator lightweight tournament semifinals with a submission victory over Martin Stapleton in the first round. It marked the fifth time in Awad's past six fights he has finished an opponent within the opening five minutes.
The method this time was a rear naked choke, applied from Stapleton's back after Awad briefly moved to full mount. Referee Jason Herzog stopped the contest at the 3:46 mark.
The finish nearly came quicker than that. Stapleton (12-2) obviously wanted to be in Awad's face early, pressuring him against the cage. He ended up walking into a hard right hand that dropped him in the fight's opening moments.
Stapleton recovered and would eventually score a takedown, but that only gave Awad the opportunity to reverse position and work for the choke.
"He came straight forward," Awad said. "My plan was to pick him apart and move but he cornered me and I had no chance but to throw punches."
Awad improved to 4-2 all-time under the Bellator banner. Stapleton suffered his first setback since a submission loss to Paul Sass in July 2008.