[2] Debuting as a professional fighter eight months after he first stepped in the gym, Moxon won his first fight by third-round technical knockout against Onur Yudical.

He rose to prominence by winning the ISKA South Pacific Middleweight (−75 kg/165 lb) Championship early in his career, and moved to Sydney to train under Peter Graham at the Boxing Works gym.

On 10 July 2010, he made his K-1 debut against Kenmun at the K-1 World Grand Prix 2010 in Canberra, and took a split decision over the tall Japanese fighter.

Following this, he went on a run, taking wins over Harlee Avison,[8] Bruce Macfie[9] and Wes Capper[10][11] to set him up for a fight with Frank Giorgi in Melbourne, Australia on 28 April 2012.

[15] By this point in his career, Moxon had accumulated a record of 29–4–1 with 19 knockouts, which attracted top promotion Glory, with whom he signed in September 2012.

[16] Around this time Moxon also made the move back from Sydney to his native state of Victoria (Australia), near the area where he grew up.

He was expected to fight Fadi Merza for the Austrian veteran's WKA World Middleweight (−72.5 kg/160 lb) title on 20 October 2012 in Melbourne[17] but the bout was cancelled and Moxon instead went up against Giannis Mixalopoulos at Brute Force 21 on 18 November 2012, knocking the Greek down in round three before winning unanimous decision.

[18][19] Moxon ended 2012 with a win over Mostafa Abdollahi at Kings of Kombat 8 on 8 December 2012 after Dzhabar Askerov withdrew from the fight.

[21] Kicking off his 2013 campaign, Moxon fought Yohan Lidon for the A1 World Middleweight (−73 kg/160 lb) title in Melbourne on 22 February 2013, losing a close split decision.

Moxon defeated Gökhan Türkyılmaz via 2nd Round KO in Istanbul, Turkey on 31 May 2013 to win the A1 World Middleweight (73 kg/160 lb) title.

[32][33] Moxon defeated Harley Love from New Zealand in a 4-round boxing match on his "Gold Rush" fight show in Ballarat, Australia on 14 Dec 2013 via a 1st Round TKO stoppage.

This move also meant travelling 1 hour most weeks for training at Barbarian Muay Thai Gym in Ballarat, which Steve relished.

In early Sept, Moxon was invited to fight Muay Thai legend and K1 star Buakaw Banchamek as the main event in the Top King World Series in Paris, France, on 1 November 2014.

Moxon kicked off 2015 with a huge win against leading fighter and GLORY number 4 ranked Aikpracha Meenayothin on 3 January in his debut on Kunlun Fight 15: The World MAX Return in Nanjing, China.