By Jake Donovan
 
It took several months to finalize terms for the welterweight showdown between Keith Thurman and Shawn Porter, but a much quicker turnaround has been enjoyed in piecing together the undercard.

BoxingScene.com has learned that the March 12 card – which takes place at Mohegan Sun Casino in Uncasville, Connecticut – will feature a full night of action carried over two separate telecasts on Showtime and CBS.

The main event will air live on CBS in primetime (8:30 p.m. ET), following a full day and early evening’s worth of college basketball action in the final weekend before the NCAA March Madness tournament commences. The lead-in will be a featherweight matchup of former three-division champs, as Abner Mares will face Fernando Montiel in what on paper suggests a can’t miss featherweight fight.

Mares (29-2-1, 15KOs) at one time owned perhaps the toughest resume among active world champions. The 2004 Mexican Olympian fought for his first title in May '10, battling to a disputed 12-round draw with Yhonny Perez.

Talks of a rematch were pre-empted by the forming of the Showtime Bantamweight Tournament, with Mares claiming top honors after outpointing Joseph Agbeko in the Aug, '11 finals, repeating the feat in a rematch later that December. Agbeko scored a revenge win over Perez in Dec. '10, having lost his title to the Colombian boxer 14 months prior, while Mares edged former two-division champ Vic Darchinyan to reach the finals. 

From there, Mares went on to capture titles at super bantamweight and featherweight, emerging as a consensus choice for one of the Top 10 pound-for-pound fighters in the sport. His world came crashing down, however, in a shocking 1st round knockout loss to Jhonny Gonzalez in Aug. '13. 

The loss temporarily derailed plans for a hoped-for future showdown with Leo Santa Cruz, who stopped Vic Terrazas in three rounds to win a super bantamweight title on the same show. The two would eventually collide, with Mares - who'd won three straight heading into the fight - came up just short as Santa Cruz claimed a decision and a vacant featherweight title in their clash last August, which aired live in primetime on ESPN. 

Montiel (54-5-2, 39KOs) recently entered his 20th year in the pro ranks, but the former three-division champ still has plenty of life left in him. His first title win came way back in Dec. '00, stopping Isidro Garcia in seven rounds to claim a flyweight title.

The reign lasted 18 months before moving up to super flyweight, where he claimed his second title in June '02. His run ended the following August, dropping a 12-round decision to Mark 'Too Sharp' Johnson, now a Hall of Fame entrant.

Montiel hopes to add to his credentials for potential enshrinement one day. His 18-4 record in title fights certainly helps, as did a career-resurrecting knockout win over Hozumi Hasegawa in their April '10 title unification bout on the road in Japan. While riding high as a kite, he was brought crashing back down to earth in a devastating 2nd round knockout loss to Nonito Donaire in Feb. '11. 

His lone other title action since then came in his most recent ring appearance, a competitive points loss to featherweight beltholder Lee Selby last October. The loss snapped an eight-fight win streak.

Inclusion of the fight helps expand the targeted audience for CBS' first offering of primetime boxing in nearly 40 years. 

As previously reported by BoxingScene.com, the card will also feature a non-title match between light heavyweights Edwin Rodriguez and Thomas Williams Jr.

The exact placement of the bout wasn’t made clear as the piecing together of the two shows was still being discussed. It is still being decided where it can fit, while the Showtime card - once approved - will be headlined by Gary Russell Jr. in a featherweight title defense.

Event handlers have an opponent in mind for Russell Jr., but declined to discuss as the fight is still being finalized.

The primetime CBS portion of the show will mark the first time in nearly 40 years that boxing will appear on the free-to-air network in such capacity. The last one marked a historic occasion, when 1976 Olympic Gold medalist Leon Spinks – boasting a 6-0-1 pro record at the time – pulled off a shocker in edging Muhammad Ali via split decision to win the World heavyweight championship.

Thurman-Porter likely won’t measure up as a historical parallel – little if anything today can compare to an Ali event, after all – but the matchup itself is significant in plans for year two of adviser Al Haymon’s Premier Boxing Champions (PBC) series. This show itself isn’t a traditional PBC event, but is acknowledged by CBS/Showtime as “a Premier Boxing Champions blockbuster” and one of several major shows in the works over the course of this calendar year.

“Whether it’s solely PBC branding or the elements surrounding (Thurman-Porter), boxing fans can count on 10 primetime telecasts this year,” Tim Smith, vice president of communications for PBC confirmed to BoxingScene.com. “It began with our premier of PBC on Fox on January 23, with Danny Garcia beating Robert Guerrero in a thrilling main event. There is a lot more to come.”

The event will mark three times in as many ring appearances that Thurman (26-0, 22KOs) has helped launch a new network series. The unbeaten welterweight from Clearwater, Florida served in the very first PBC telecast, soundly outpointing Guerrero in their PBC on NBC primetime headliner last March. The event served as the highest-rated telecast on network or cable television in 2015.

Thurman’s next fight – and also his last to date until March 12 rolls around – kicked off the PBC on ESPN model, scoring a 7th round stoppage of Luis Collazo in his home training region in Tampa, Florida.

Porter (26-1-1, 15KOS) served in the first fight to appear in the PBC on Spike TV series, scoring a 5th round stoppage of Erick Bone – a late replacement for an injured Roberto Garcia – last March. The win was followed by his most notable in-ring achievement, outpointing Adrien Broner in their primetime NBC main event last June.

Dating back to last summer, Thurman and Porter have been in talks for a welterweight fight that carried wide speculation as to the hold up in coming to fruition. Original plans had the matchup targeted to headline a December 12 edition of PBC on NBC, but instead decided to move to the 1st quarter of 2016 to help launch a new series in the works.

Once it became apparent that it would not kick off the PBC on Fox series, plans surfaced of boxing returning to CBS in primetime, having previously appeared in Saturday and Sunday afternoon editions in 2015. Various dates in February were floated, as well as the possibility of landing on March 5 in Las Vegas. The latter suggestion fell through once the UFC announced a loaded Pay-Per-View card, shifting this event to the East Coast and one weekend later. The move actually maximizes lead-in coverage, preceded by seven hours of college basketball divisional championships and semifinals.

Jake Donovan is the managing editor of BoxingScene.com. Twitter: @JakeNDaBox