Gallen, who was hugged by Channel Nine boss David Gyngell when he stepped out of the ring after beating Wentworthville brawler Randall Rayment on the undercard to the main bout between Williams and Chauncy Welliver, showed his boxing skills had improved under the tutelage of world champion Daniel Geale and his trainer Graham Shaw by repeatedly fighting his way out of trouble with selective punching in a four-round brawl watched by a crowd of more than 6000  on free-to-air television.

It was the third professional win in Gallen's career and the 33-year-old admitted he is now looking to make the much touted bout with Williams a reality, possibly within 12 months.

Off contract with the Sharks, Gallen said he was unsure how long he would continue playing but intends to continue boxing beyond his NRL career and knows there would be strong demand for a fight between him and Williams.

"It is brewing I suppose, it has been spoken about for a couple of years now," Gallen said. "Sonny is probably a good level above me at the moment but I learn fast... which is why Graham sticks with me. He has coached world champions but he said he is impressed by how much I want to learn.

"I suppose in 12 months time I am going to have to improve a fair bit to be able to compete with Sonny but it is certainly on the cards."

After reluctantly accepting a backdated 12-month suspension for his role in the supplements program at Cronulla in 2011, Gallen was forced to miss the last three matches of 2014 with the Sharks and the Four Nations tournament for Australia and he threw himself into training with Shaw and Geale at Old Grange Boxing Gym in Campbelltown.

"I went out there every day. I would get in the car and drive out to Campbelltown, sometimes at 6am and I can't thank Daniel and Graham enough," he said. "They took me in every day and I got to train with a world champion."

As a result, he appears to have improved significantly and remained more composed under pressure than in his previous fights as Rayment, who has a MMA background, repeatedly held him and pushed him into the ropes.

"I knew he couldn't hurt me, I felt his punches and I knew he couldn't hurt," Gallen said. "But Graham said that was my biggest problem.  He said 'even though they don't hurt you they are still going to score' so I fixed that up in the third round."

Gallen will now return to training with the Sharks and said he won't look to fight again until the end of the season.

"I have just had a really good time boxing, a really good time with the Grange boys and I just want to get back to footy and put my heart and soul into footy," he said. "It is the last year of my contract and I don't know what is going to happen there. Come the end of the year I will look at it but my main goal is just to get back to footy at the moment."

Both of the other footballers on the bill enjoyed impressive wins, with teenage Sydney Roosters forward Willis Meehan stopping 35-year-old US heavyweight Freddie Miller in the second round and All Blacks star Liam Messam winning a unanimous decision over  Queenslander Rhys Sullivan.

The win was Meehan's third in the past two months since debuting on the undercard of his father Kali's fight against Kiwi heavyweight Shane Cameron on November 22 and his second knockout after stopping Alofa Solitua on December 3 in Sydney.

The fight wasn't without controversy after Meehan reacted to a punch from Miller after the bell at the end of the first round by dropping the American and the 19-year-old picked his opponent off regularly before finishing him 2.43min into the second round.

Asked afterwards whether he would choose boxing over rugby league, Meehan said: "At the moment I am pretty pleased to be able to do both and I am going to keep doing that".