LAS VEGAS – There weren’t nearly as many passionate Filipino fight fans in the building for John Dato’s fight Saturday as there will be when Manny Pacquiao boxes Yordenis Ugas a few hours later.

Those that arrived early enough watched the Filipino featherweight lose for the first time as a professional to Angel Contreras. The rugged Mexican dropped Dato in the third round and built enough of a lead to fend off Dato’s rally and won an eight-round unanimous decision on the non-televised portion of the Pacquiao-Ugas undercard.

Judges Max De Luca (78-73), Patricia Morse Jarman (77-74) and Dave Moretti (77-74) all scored the action for Contreras, who improved to 11-4-2. Dato dropped to 14-1-1.

Sensing he needed a knockout, Dato went at Contreras in the eighth and final round.

Dato caught Contreras with a right hand that affected him and made Contreras retreat about 50 seconds into the eighth round. They traded hard shots on the inside with just over a minute remaining in their fight.

Contreras connected with a thudding left to Dato’s body just after the midway point of the seventh round. Dato drilled Contreras with his own left to the body and followed up with a right hand with about 40 seconds on the clock in the seventh round.

Dato, whose nose bled, moved Contreras backward with a right hand in the middle minute of the sixth round.

Contreras’ right hand moved Dato backward 1:10 into the fifth round. Dato clipped Contreras with a right hand that got his attention with just over a minute on the clock in the fifth round.

They exchanged hard rights in the final 10 seconds of the fifth round.

Contreras cracked Dato with a left hook when there was approximately a minute to go in the fourth round. Dato landed a right hand that backed Contreras into the ropes late in the fourth round.

A right uppercut by Contreras sent Dato to the canvas with just under two minutes remaining in the third round. Dato got off the seat of his trunks and beat Hoyle’s count.

Dato fought back once the action continued, though Contreras seemed to be wearing down Dato.

Dato landed a right hand early in the second round, but Contreras countered with a left hook that made Dato retreat. Contreras’ right hand landed flush with about 35 seconds to go in the second round.

Dato drilled Contreras with a right hand that back him up with just over a minute to go in the first round. Contreras caught Dato with a left hook just before the first round ended.

In the previous fight Saturday, Mickel Clements succeeded in his pro debut.

The 18-year-old Clements out-boxed Eliseo Villalobos in their non-televised, four-round lightweight bout at T-Mobile Arena. All three judges scored it a shutout for Clements, 40-36.

Clements, of Linden, Michigan, is a stablemate of junior middleweight prospect Joey Spencer. Villalobos, of Simi Valley, California, slipped to 1-2.

Clements caught Villalobos with a left hand when there was about a minute to go in the fourth and final round. Villalobos blasted Clements with a right hand several seconds later.

They traded hard shots in the final 20 seconds of a competitive final round.

Clements cracked Villalobos with a right hand 1:20 into the third round. Nearly a later, Clements caught Villalobos with a left hand in an exchange.

Clements controlled the action during the second round, but he wasn’t able to hurt Villalobos the he did during the opening round. Clements wobbled Villalobos with a left hand at the halfway point of the opening round.

In the bout before Clements won his pro debut, one of Errol Spence Jr.’s stablemates settled for a draw on the day Spence was supposed to battle Pacquiao.

Burley Brooks and Cameron Rivera fought to a split draw in their non-televised six-round rematch at a mostly empty T-Mobile Arena. Judge Chris Migliore scored their immediate rematch for Rivera, 58-56, but judge Richard Ocasio scored their light heavyweight fight 59-55 for Brooks and judge David Sutherland had it even, 57-57.

Rivera (9-6-4, 6 KOs) upset Brooks by unanimous decision April 20 in a six-round light heavyweight fight FS1 televised from Shrine Auditorium & Expo Hall in Los Angeles. Brooks (6-2-1, 5 KOs) lost a second straight fight that night and desperately needed to beat Rivera in their immediate rematch.

Their fight followed more than a one-hour break in the Pacquiao-Yordenis Ugas undercard following FOX’s three-fight telecast. Fans were allowed to enter T-Mobile Arena just as the Brooks-Rivera rematch began.

The sparse crowd witnessed a very competitive rematch between Dallas’ Brooks and Rivera, of Fife, Washington.

Rivera landed several hard right hands during the sixth and final round, which Rivera seemingly won. After a strong showing in the fourth round, Brooks worked well off his jab throughout the fifth round and again out-landed Rivera.

Brooks countered the left Rivera landed with a right that backed him up just after the midway mark of the fourth round. Brooks knocked Rivera off balance with a right hand that landed with just under a minute remaining in the fourth round.

Rivera landed several jabs and two right hands over Brooks’ jab in the third round. Brooks rallied later in the third round.

Rivera’s left-right combination moved Brooks into the ropes in the final minute of the second round. Brooks gathered himself and later landed a flush right uppercut that got Rivera’s attention.

Despite the draw, Brooks looked sharper immediately Saturday than in their initial meeting. He ripped a left to Rivera’s body almost as soon as their fight started and controlled the action throughout the first round.

Four months earlier, judges Eddie Hernandez Sr. (58-55), Robert Hoyle (57-56) and Fernando Villarreal (57-56) scored their first fight for Rivera.

Brooks had a point deducted during the sixth round for repeatedly landing low blows. That deserved deduction was the difference between Brooks losing a unanimous decision and their fight being declared a majority draw.

Three hours before Brooks and Rivera fought again Saturday, a huge American heavyweight remained undefeated on the televised portion of the Pacquiao-Ugas undercard.

Fans hadn’t been admitted into T-Mobile Arena when he fought, but Steven Torres took advantage of his national television exposure by stopping Justin Rolfe in the first round of a scheduled four-rounder FOX aired. Referee Robert Hoyle stepped between them to stop their fight 2:33 into it, with Rolfe still on his feet.

Torres (5-0, 5 KOs), of Reading, Pennsylvania, didn’t drop Rolfe, but the 6-feet-7, 250-pound prospect landed several flush punches before Hoyle halted their fight. The 5-feet-10 Rolfe, of Fairfield, Maine, slipped to 6-3-1 and lost by knockout for the first time in three years as a pro.

Rolfe aggressively came forward as soon as their fight started to get inside on Torres. Rolfe connected with a left hook as Torres backed into the ropes.

Torres drilled Rolfe with a straight right hand with just under a minute to go in the first round. That shot knocked Rolfe off balance.

Torres continued to throw huge right hands. Rolfe didn’t throw many punches back and bent over, which was why Hoyle stepped in to stop the one-sided fight.

In the first fight Saturday, Jose Valenzuela battered and bloodied Donte Strayhorn until referee Raul Caiz Jr. decided Strayhorn shouldn’t take more punishment. Caiz stopped a lightweight fight FOX televised at 1:29 of the fourth round.

The Mexican-born Valenzuela, a 22-year-old prospect who resides in Seattle, improved to 9-0 and produced his sixth knockout. Cincinnati’s Strayhorn (12-4, 4 KOs) displayed tremendous toughness, but he lost inside the distance for the first time in 16 professional fights.

Valenzuela scored a knockdown early in the first round and spent most of their fight walking down a game Strayhorn, who took this fight on about one week’s notice. He bloodied Strayhorn’s nose in the third round and continually attacked Strayhorn’s body.

Valenzuela’s straight left penetrated Strayhorn’s guard early in the third round and snapped his head back. Then Valenzuela resumed his brutal body attack.

A right-left combination by Valenzuela backed Strayhorn into the ropes with less than a minute to go in the third round. Toward the end of the third round, Strayhorn caught Valenzuela with a right uppercut that Valenzuela took well.

After scoring a knockdown during the first round, Valenzuela battered Strayhorn to his body throughout the second round. Strayhorn kept trying, but he took a lot of heavy shots in those second three minutes.

A sweeping left hand by Valenzuela caused Strayhorn to stumble backward and touch the canvas with his right glove, which counted as a knockdown about 25 seconds into their fight.

Strayhorn responded by going after Valenzuela, who fired back with head and body shots of his own. Another left hand by Valenzuela backed Strayhorn into the ropes with just over 30 seconds to go in the opening round.

Keith Idec is a senior writer/columnist for krikya360.com. He can be reached on Twitter @Idecboxing.