Just 18 months ago Antonio was plying his trade for Ryman Premier side Tooting & Mitcham.
Antonio told BBC Radio Solent: "We're not in the final yet, but if we could do it, it would fulfil a dream for me."
He added: "The experienced lads reminded us that we've only done half of the job and we've got nothing to celebrate.
"We've got to make sure we prepare properly for all the games coming up, starting with the FA Cup game against Ipswich.
"But having a lead to take into the second-leg against MK Dons will hopefully take the pressure off us a little."
Pacy winger Antonio initially joined Saints on a month's loan from Reading back in October, but has since had that deal extended until the end of the season.
"Under this manager (Alan Pardew) it's all about performance, and if you don't perform, you're dropped. I know I've got to prove to him that I'm worthy of my place in the team."
The second-leg of the JPT Southern Final takes place on 9 February at St Mary's, with the winners meeting Carlisle or Leeds in the final at Wembley Stadium on 28 March.
Source: BBC Sport
Source: BBC Sport