Machida (22-5) hurt Dollaway with a left kick to the body less than one minute in, before eventually finishing him with punches on the ground. The middleweight bout headlined a UFC Fight Night event on Saturday at Jose Correa Arena in Sao Paulo, Brazil.
"CB is a very tough fighter, but the kick landed and I saw he felt it," Machida said. "I went in for the finish."
It is the ninth knockout of Machida's career and 11th finish overall. Arguably none have been more dominant than Saturday, however. According to immediate cageside stats, Machida landed 12 significant strikes, while Dollaway (15-6) landed zero.
It was a somewhat puzzling strategy employed by Dollaway, a former All American NCAA wrestler at Arizona State University. The 31-year-old came out pawing his jab at Machida, while circling to his left away from the Brazilian's power.
He seemed willing to fight at the former UFC light heavyweight champion's range and did not attempt a takedown. Machida's kick was a direct shot to Dollaway's liver, just under the rib cage on his right side. He immediately winced and covered up, falling defensively to his butt and then his side until the fight was called.
Machida rebounded from a unanimous decision loss to Chris Weidman in a failed title bid at UFC 175 in July. Immediately after the win, UFC middleweight Luke Rockhold wrote on Twitter: (Machida) looked good. I'm ready when you are (UFC president) Dana White."
Machida said he would wait on the promotion for his next assignment.
"I'll wait for the boss, Dana White," Machida said. "My objective is always the belt."
Dollaway's two-fight winning streak was snapped. He had won four of his last five prior to the loss. It is the third knockout loss of his career.
Barao bounces back with win
A forgettable year for Renan Barao ended on a positive note, at least.
The former UFC champion kicked off 2014 with a first-round knockout against Urijah Faber in February, but surrendered the belt three months later in a lopsided TKO loss to TJ Dillashaw. The 27-year-old was scheduled into an immediate rematch against Dillashaw in August, but was forced off the card when he fainted trying to make weight the day before the fight.
The Brazilian got back to his winning ways against Gagnon (12-3), who proved to be a game opponent -- even if he never truly threatened to beat the former champ.
"It was a tough fight," Barao said. "He had some great wins by submission. I tried to feel the fight and got the finish. The goal was to win and now think about the belt again."
Barao's standup was on point early, as he tagged Gagnon with outside leg kicks and dropped him with a counter left hook late in the opening round. Gagnon didn't wilt under the offense, however, and consistently looked to walk forward and let his hands go. He hit Barao with several left hooks of his own and lead uppercuts.
Known as submission specialist, Gagnon attempted to take Barao down throughout the three-round bout but the task proved to be over his head. He aggressively worked into the clinch and pressured Barao backward into the fence, but failed to ever drag him down. Yamasaki separated several stalemates on the cage wall in the second and third rounds.
Midway through the final round, Barao took Gagnon down in a scramble and moved into full mount. He quickly transitioned into the arm-triangle, which produced the tap with just over one minute remaining.
Dillashaw (11-2) is expected to defend his title against former champion Dominick Cruz in early 2015. Barao is a potential candidate for the winner. He improved his UFC record to 8-1 with the win. Gagnon suffered his first setback since July 2012.
Cummins works over Carlos
Cummins (7-1) improved to 3-1 in the UFC with a unanimous decision victory against Antonio Carlos Jr. Cummins is now 3-0 since an infamous first-round TKO loss to Cormier in his promotional debut.
All three judges scored the light heavyweight contest for Cummins, 30-27.
"He did everything we expected, and for the most part we were ready for it," Cummins said. "It was just a matter of following the game plan. He is a great jiu-jitsu fighter, so I needed to make sure I had the control over his hands and posture.
"All credit to him; he is a really tough guy."
Offensive wrestling was the name of Cummins' game again in this one, as the former All-American NCAA wrestler took Carlos (4-1) down at ease in each of the three rounds. Carlos threatened at times with leglocks from the bottom, but was more or less shut down by Cummins' top game.
Carlos' best work from the bottom came early, as he attacked Cummins' left leg off his back. Cummins remained calm though, removing himself from danger late in the round and eventually landing several good elbows out of side control.
It was a similar story in the second and third rounds, as Cummins scored takedowns in the opening minute of each frame and showed no hesitancy going to work in Carlos' guard. Carlos, a winner of "The Ultimate Fighter" Brazil reality series, looked gassed toward the end of the fight and gave up easy takedowns as he wound up on home-run right hands on the feet.
In the final minute, Carlos showed a little life as he took Cummins' back in a scramble. He finished the fight in the advantageous position but never came close to scoring a submission.
"I couldn't get the win; he is a tough guy," Carlos said. "I got two injections [in my shoulder and rib cage] recently, but this is not an excuse. He deserved the win. I will come back better, and I will drop to the middleweight division."