Top Rank has added an interesting heavyweight fight to its Xavier Martinez-Robson Conceicao undercard Saturday night. has learned that unbeaten heavyweight prospect Stephan Shaw will oppose Joey Dawejko in an eight-rounder that’ll headline the ESPN+ portion of an undercard from Hard Rock Hotel & Casino in Tulsa, Oklahoma. Top Rank has signed Shaw (15-0, 11 KOs), who is also promoted by DiBella Entertainment, to a multi-year co-promotional agreement.

The 29-year-old Shaw most recently knocked out Nick Davis (then 6-2) in the first round August 27 in Plant City, Florida. The St. Louis native has shown some promise, but the 6-foot-4, 235-pound Shaw’s career has progressed pretty slowly since he made his pro debut in December 2013.

The typically durable Dawejko (21-9-4, 12 KOs) was knocked out by hard-hitting Kazakh southpaw Zhan Kossobutskiy (17-0, 16 KOs) in the second round of his last bout, which took place August 21 in Hamburg, Germany.

Philadelphia’s Dawejko, 31, has been beaten inside the distance just twice during his 12-year, 34-fight pro career. He has fought former IBF champ Charles Martin, who stopped him after four rounds, and has gone the 10-round distance in losses to former or current contenders Amir Mansour, Bryant Jennings, Andrey Fedosov, Sergey Kuzmin and Frank Sanchez along the way.

Martinez (17-0, 11 KOs), a 130-pound contender from Sacramento, will make his Top Rank debut when he battles Brazil’s Robson Conceicao in the 10-round main event.

Before he signed with Bob Arum’s Top Rank recently, the 24-year-old Martinez was promoted by Floyd Mayweather’s company. The 33-year-old Conceicao (16-1, 8 KOs) tested unbeaten WBC super featherweight champ Oscar Valdez during his most recent action, but Mexico’s Valdez (30-0, 23 KOs) won their 12-rounder by unanimous decision September 10 at Casino del Sol in Tucson, Arizona.

The co-feature Saturday night will pit Mexican junior lightweight contender Rene Tellez (16-1, 10 KOs) against Luis Melendez (17-1, 13 KOs) in a 10-rounder that’ll begin ESPN’s telecast at 10 p.m. ET and 7 p.m. PT. Top Rank’s undercard coverage is set to start at 6 p.m. ET and 3 p.m. PT on ESPN+, the network’s $7-per-month streaming service.

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