Mattice, 27 years-old of Cleveland, Ohio has amassed a record of 9-0 with seven knockouts.
Mattice had an amateur record of 72-18, and was a three-time Ohio State Golden Gloves champion. He was a Ringside World champion in 2014, and was a Bronze medal winner in the USA National Tournament in 2014.
Mattice turned professional in 2014, and has faced veteran opponents throughout his nine-fight career.
Mattice is coming off a 6th round stoppage over John David Charles on July 29th in Raleigh, North Carolina.
"I am very happy to sign with GH3 Promotions, and I am looking for big things. I know GH3 Promotions can help me become world champion,"said Mattice.
"I am looking to fight three more times this year, and I am already scheduled to fight on September 16th. If everything comes out alright, I will also fight in November and December. I am looking for 2018 as being a big year, and I should start being on some of the prospect lists."
Mattice, who is a humble kid, works at a grocery store where he is a cashier and he also stocks shelves."
Said Vito Mielnicki of GH3 Promotions, "Thomas is an excellent prospect. He has a very solid amateur pedigree and has shown good boxing skills and good power in his first nine fights. He has not been babied and we will continue to step him up. I see big things in his future."
"He is a beautiful kid, and he is very down to earth," said Mattice's manager, Chances Aurelius.
"He eats, drinks, and sleeps boxing. Earlier this year, I saw him fight in Atlanta, and he performed very well, and I signed him. He has a tremendous work ethic, and he has a regular job at the store.He grew up on the rough side of town, but he is dedicated to boxing, and he has a chance to do great things in the sport."
Mattice is trained by Push Davis. Davis echoed the words of his manager and promoter.
"He is a dedicated kid, and he trains very hard. He has fought in other people's backyards, and you do';t see that often by a young fighter. He has not had any easy fights, and he has fought good competition. When describing his styles, he is a boxer who can punch, and has a nice body attack. He can move around the ring well and has decent power."
For more information on GH3 Promotions, Contact:
Marc Abrams-- firstname.lastname@example.org or 856 287 7611