He was told there was no separate purse but cleared up to beat Mark King 3-0.
The 34-year-old appeared content to end on the pink in the final frame and had to be persuaded to pot the black.
After potting the first red and black in frame three O'Sullivan halted proceedings to ask what the prize for a 147 was, only to be eventually told there was no additional purse and only a £4,000 sum for the highest break.
He potted some outstanding balls in his maximum, achieved in barely 10 minutes - even with the delay when researching about the 147 prize - but shook hands with King after disposing of the pink.
Referee Jan Verhaas persuaded O'Sullivan to finish the break and he duly slammed in the black in nonchalant fashion.
"I wasn't going to pot the black to be honest with you because I asked the ref and was told there was no break prize for a 147," O'Sullivan admitted to the BBC.
"I wanted to make sure because if there was a decent prize then I would definitely have gone for it and I thought I might as well go for it anyway.
"Jan talked me into it [potting the black]. My whole thing was I was going to make 140 and leave the black What's the point of making a 147 if they're only going to give you four grand for it?
"I'm surprised. They're getting stingier. I thought Barry Hearn was supposed to be putting more money into the game, not taking it out.
"I've had loads of 147s so I don't really get excited by it and thought I needed to give myself something to go for. I just thought 'why not?'"
My Betfair screen shot shows a £4 profit but believe me I am really happy about that as at one stage it was not looking to clever. I had a heavy horse lay that won in the first race and from then on it was damage limitation. I managed to get the majority of it back on a few other nags.
This morning i spent a couple of hours pouring over the in play football matches on Betfair and after checking up on some stats I came up with a few games that I wanted to get involved with. Amazingly they all went pretty much too plan ,I suppose the only issue was that I bailed out in all of them and greened up because I couldnt face the stress of watching the market waiting for the dreaded suspend sign to come up, followed by the couple of minute wait to see if its gone for or against you. I think thats why I enjoy the horse racing because if you are going to do your nuts its over quickly, where as football and tennis is sometimes like a death by a thousand cuts as you sit stewing at the PC. Anyway all the results went my way and if I hadnt of got out I would have had a £ 360 profit instead of £120, but I was taught that "your first profit is your best profit."
So it was a bit of a role reversal as the profits came from my own bets. I had eight bets with two losses, five placing at 20/1 Dramatic Jewel, 14/1 Trikirk, 12/1 Spinning Bailwick, 10/1 Tayacoba and 15/2 Strictly Lambadda and thankfully a winner at 8/1.
The total profit from these was £ 370. I cant be bothered to cut and paste them all so here's the winner.
The Irish racing has been good to me over the last six weeks and long may it continue.