Jai Opetaia can do without the birthday wishes from his upcoming opponent.

He will gladly settle for the championship belt that Mairis Briedis possesses as his present.

“That’s all that matters right now, hearing those words,” Opetaia commented during the final pre-fight press conference Thursday afternoon preceding his challenge of Briedis’ IBF title. “None of that birthday stuff, just hearing ‘And New....'”

The scheduled 12-round lineal/IBF cruiserweight championship clash between Latvia’s Briedis and Sydney’s Opetaia takes place Saturday, airing live on ESPN+ (5:00 a.m. ET/2:00 a.m. PT) and Australia Main Event from Gold Coast Convention Centre in Broadbeach, Australia. Briedis (28-1, 20KOs) attempts the second defense of his second title reign and seventh overall title fight.

Opetaia (21-0, 17KOs) challenges for his first major title. The unbeaten contender made history for his home country, becoming the youngest boxer to represent Australia as a 16-year-old in the 2012 London Olympics. The Australian southpaw—who turned 27 on Thursday—hasn’t quite risen to the same level of prominence as a pro, going from mid-level competition straight to the top in his challenge of Briedis, who remains remarkably preserved at 37 years of age.

Despite the gap in experience and level of competition, Brieidis enters as just a -210 betting favorite according to DraftKings Sportsbook, while Opetaia is a surprisingly low +165 underdog. Still, the undefeated contender remains convinced that few give him much of a chance to prevail.

“I definitely think I’m being underestimated,” noted Opetaia. “But he’s been training hard. He’s been at the top for a long time. I know his coach is getting him ready. He better not be underestimating me because I’m ready. I’m ready to go in there and become a world champion.

“I know this is not going to be a tough fight. I’m not expecting to go on there and box his ears off.  I’m ready for a tough fight. I’m ready for those deep waters. I’m ready to dig deep and earn this belt.”

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox