Hard-hitting Polish contender Mateusz Masternak (39-4, 26 KOs) will battle once-beaten Stivens Bujaj (16-1-1, 11 KOs) in a 10-round World Boxing Super Series cruiserweight reserve match on Saturday, October 21 at Prudential Center in Newark, N.J.

Additional action will feature a 10-round super welterweight bout between unbeaten Polish contender Maciej Sulecki (25-0, 10 KOs) and former title challenger Jack Culcay (22-2, 11 KOs).

The October 21 event is headlined by IBF champion Murat "Iron" Gassiev and former world champion Krzysztof Wlodarczyk squaring-off in World Boxing Super Series cruiserweight quarter-final action.

"This is going to be a fantastic show for fans to come out and get a night full of action on October 21 in Newark, New Jersey," said Richard Schaefer, Chairman and CEO of Ringstar Sports. "Polish pride will be in full force as Mateusz Masternak and undefeated Maciej Sulecki take on tough opponents in important matchups as they chase their world title aspirations. This of course will all lead up to the main event and the final World Boxing Super Series cruiserweight quarter-final pitting the champion Murat Gassiev against the former champion from Poland, Krzysztof Wlodarczyk."

Promoted by Ringstar Sports in association with World Boxing Super Series, tickets for the live event are on sale now and are available at Ticketmaster.com. Tickets are also available to purchase at the Prudential Center box office.

"In my top form I know that I can beat better fighters than Bujaj," said Masternak. "I don't think he can hurt me. Every fight is important, boxing teaches you that every day. But Bujaj is a stepping stone for me to bigger fights. He is saying that he beat me in sparring a few years ago, but how well could it have gone if he departed faster than he arrived? I have no time to make a mistake and lose a fight like this so I will be ready for anything when we enter the ring."

Fighting out of Wroclaw, Poland, Masternak has fought a slew of top champions and challengers in the cruiserweight division and enters this fight the winner of his last three contests. The 30-year-old has battled Tony Bellew, Grigory Drozd and Youri Kalenga while also picking up the European cruiserweight championship with a victory over Juho Haapoja. Masternak has fought in nine countries throughout his career and returns to the fight the U.S. for the first time since his fourth pro bout in 2006.

"Get ready to see the best Stivens Bujaj ever," said Bujaj. "I've been training two, sometimes three times a day. I've been in this sport since I was 15 years old, and it all comes down to this moment. This is my world championship. It's going to be the fight of my life and I'm ready to do whatever it takes. I've sparred Masternak before and I dominated for eight rounds and they sent me home. I'm ready to finish what I started on October 21!"

An Albanian fighter living in New York, Bujaj was a two-time New York Golden Gloves champion before turning pro in 2010 and going unbeaten in his first 18 pro bouts. The 27-year-old won three times in 2016, including a victory over then unbeaten Sergio Ramirez before dropping a bout to undefeated Constantin Bejenaru. Bujaj has been hampered by injuries during his career but returns to the ring healthy and ready to resume his climb to the top of the division. 

Representing Warsaw, Poland, Sulecki pulled off his most impressive victory to date last year when he stopped then unbeaten contender Hugo Centeno Jr. in the 10th and final round of their fight. The 28-year-old has picked up victories over Damiam Bonelli and Michi Munoz since then as he seeks a world title at 154-pounds. Sulecki will return to Prudential Center for the second time after knocking out Jose Miguel Berrio in 2015 at the venue in Newark.

Culcay was originally born in Ecuador but grew up in Germany and in 2008 he represented the Germans at the 2008 Olympics. The 32-year-old was dominant in winning his first 14 pro fights and picking up the WBA inter-continental super welterweight title. Culcay put together another seven-fight winning streak and won the WBA interim super welterweight title before dropping a world title bout to Demetrius Andrade by close split-decision in March.