Lando Vannata woke up Saturday morning and began his preparations for his bout scheduled for the early prelims of UFC 234. But then he got a call informing him that he had been moved up to the co-main event, and he made the most of the opportunity on the bigger stage, dominating Marcos Rosa Mariano before finishing him with a kimura submission with five seconds remaining in the first round at Rod Laver Arena in Melbourne, Australia.

Vannata (10-3-2), who had been winless in his past four fights (two losses, two draws) after making a huge splash in his UFC debut back in 2016 by nearly upsetting Tony Ferguson, dominated his Brazilian opponent from the start. He dropped Mariano (6-5) midway through the round and pounced on him and didn't let him get back to his feet, dropping punches and elbows from inside guard.

Mariano seemed to have no answer for getting the fight back to standing. He was making his UFC debut.

"We knew he's a decent striker," said Vannata, "so we wanted to take him down."

The fight was moved up on the card after the scheduled main event, a middleweight title fight between champion Robert Whittaker and Kelvin Gastelum, was canceled because Whittaker was hospitalized for abdominal surgery. The original co-main, between the legendary Anderson Silva and unbeaten rising star Israel Adesanya, was moved up to the top of the marquee.

"I woke up, felt good, was about to go down to the bus [to the arena] and I got the news," said Vannata. "So I went and got food and went back to sleep."

Ricky Simon cruised to a unanimous decision victory against top BJJ practitioner Rani Yahya at UFC 234. Asanka Brendon Ratnayake for ESPN

Ricky Simon defeats Rani Yahya by unanimous decision

Simon dropped his Brazilian opponent several times but let him up every time in the first two rounds, knowing full well that Yahya (26-10) has had 20 submissions. But the American landed punches all fight, stopped all 10 takedown attempts -- and finished the fight boldly on top of a beaten-down opponent, dropping down punches right to the final horn as he won his eighth in a row.

"He's a specialist," Simon said of Yahya. "His jiu-jitsu is, I feel like, one of the best in the UFC. I kind of picture him as the Demian Maia of the bantamweight division."

Two of the judges simply gave Simon (15-1) all three rounds, while the other scorecard was him a 30-25 winner. The 26-year-old fights out of Vancouver, Washington.

Yahya, 34, had won seven of eight.

Montana De La Rosa dominated Nadia Kassem at UFC 234, winning by second-round TKO. Asanka Brendon Ratnayake for ESPN

Montana De La Rosa defeats Nadia Kassem by second-round armbar

De La Rosa was dominant from start to finish, coming out of her corner aggressively to take Kassem to the canvas and keeping her there for much of Round 1. She then repeated the process in the second round of the flyweight bout before securing an armbar that elicited a verbal submission at 2:37.

The Texan (10-4) won for the third straight time in the battle of 23-year-olds, handing Kassem (5-1) her first career defeat. The Aussie withstood a beatdown and a several submission attempts before the relentless De La Rosa got the finish for her third straight win.

Jim Crute has won all 10 of his fights in the UFC, including at UFC 234 on Saturday night against Sam Alvey. Asanka Brendon Ratnayake for ESPN

Jim Crute defeats Sam Alvey by first-round TKO

Crute dropped Alvey with a crisp right hand midway through Round 1 and walked away from his hurt opponent, figuring the fight was over. But referee Marc Goddard allowed the light heavyweights to continue, so the unbeaten Aussie pursued his wobbly American opponent, took him back to the mat and finished him with an unanswered succession of punches before Goddard jumped in at 2:49 of the round.

Alvey (33-12) protested the finish, but he had put up less resistance while being beaten down on the canvas by the 22-year-old Crute (10-0), the youngest fighter on the card.

Devonte Smith defeats Dong Hyun Ma by first-round TKO

Smith scored his fourth straight first-round knockout and his sixth win in a row, all finishes, hurting Ma with a straight right hand and following with more punches that floored the South Korean. He then added hammerfists that finished the job at 3:53 of Round 1. The American lightweight is 10-1; Ma (16-9-3) saw a three-fight winning streak end violently.

Shane Young defeats Austin Arnett by unanimous decision

Young relentlessly moved forward for three rounds, throwing punches the whole time, and even though Arnett avoided many of them, the punches kept coming from the New Zealander. They started landing hard in the final minute of each round, securing 30-27 scorecards from all three judges. Young (13-4) won for the seventh time in his past eight; Arnett, who seemed content to land single punches while moving backward, lost his fourth in his past five. The American fell to 16-6.

Kai Kara-France defeats Raulian Paiva by split decision

Kara-France landed several big shots over the three rounds, and although none of them stopped Paiva from continually stalking him, the accumulated punches and kicks impressed two of the three judges. All three scored the bout 29-28, with the 25-year-old New Zealander (18-7) getting the nod to extend his winning streak to seven. Paiva (18-2), a 23-year-old Brazilian flyweight making his UFC debut, saw a 12-fight winning streak end.

Kyung Ho Kang defeated Teruto Ishihara by first-round rear-naked choke

Kang and Ishihara went "rock 'em, sock 'em" for a good stretch of Round 1, flinging wild punches and kicks at each other, both fighters living dangerously in the standup. But it was when the fight went to the canvas that Kang had too much technique for his Japanese opponent, sinking in a rear-naked choke that finished Ishihara (10-7-2) at 3:59 of the round, with referee Herb Dean ending the fight after Ishihara did not tap out. The South Korean Kang (14-8) has won three of his past four.

play 1:42 Kara-France wins via split decision Kai Kara-France defeats Raulian Paiva via split decision in the prelims of UFC 234.

Jalin Turner defeats Callan Potter by first-round KO

Turner wasted no time in scoring his first UFC victory, catching Potter with a crisp counter hook in one of the fight's first exchanges, then following with kicks and punches that finished the Aussie just 53 seconds in. The California-based lightweight (7-4) lost his debut in the promotion last summer, and Potter (17-7), who fights out of Melbourne, was in his first UFC fight at age 34.

Jonathan Martinez defeats Wuliji Buren by unanimous decision

Martinez was taken down in all three rounds but managed a reversal each time and earned his first UFC victory by staying one step ahead of Wuliji in a crowd-pleasing, bantamweight, grappling matchup to open the show. All three judges scored the fight for the Texan (10-2), two by 30-27 and the other by 29-28. Buren (11-7), from China, lost for the third time in a row.