piss in a pint 

New Zealand and Australian slang/phrase which is used during a game or activity when a participant immediately develops a clear understanding of the rules and performs well.

Amy has just learnt the card game 'shit head' and is already playing the game strategically. She wins or preforms well in the first game she plays. Piss in a pint.

Or

Amy has just played her last card in a game that she has just learnt and wins the round. Another player says to her 'piss in a pint'.

piss in a pint by Joiful20 May 19, 2018

piss in a pint 

When someone gets really good at something after only trying it a few times. It's not a fluke; that just have mad skills. Real good, real fast.

Amy just learnt the card head game ''shit head'. She won after three rounds of playing. Piss in a pint.

piss in a pint by ThugsofHindustan May 11, 2018