With time ticking down and Taieri leading 20-19, Haugh took the ball to the line, chipped his opponent, regathered and beat two tacklers on an angled run to the corner.
The third defender got him but flanker Jordan Dwight was there in support, scooped it up and scored.
What a moment. What a play.
Southern defied just about all the odds to win.
Taieri was unbeaten leading into the match and everyone bar the Magpies' faithful was predicting a third consecutiive title for the Eels.
Earlier, Taieri had the better of the opening 10 minutes, but had just a penalty to Brayden Laing to show for it.
Southern shook off some early nerves and its big ball carriers started getting in behind the Taieri defensive line.
Jack Leslie knocked over a couple of penalties to put the Eels under some scoreboard pressure.
But the defending champions set-up a lineout drive from 8m out and the hooker Brady Robertson got in the boot of the maul and drove over.
Southern snatched back the lead when the experienced Mitchell Scott got in a tangle in the midfield and was penalised for shepparding.
Scott quickly redeemed himself, though. He snatched an intercept to snuff out a promising move and scampered 20m.
Southern infringed at the ruck and Laing knocked over a penalty from 40m out to put the Eels up 11-9.
But there was some twists left in the opening spell.
Southern was battering away at the line, but was meet with some stiff resistance until first five Jack Leslie stepped his way around a couple of tacklers and scored between the posts.
Laing cut the gap just before the break with a third penalty.
The teams traded penalties but a key moment came when Southern veteran No 8 Mika Mafi was sent to the bin midway through the second spell.
Taieri had an attacking scrum but could not make headway and moved it to the right.
Magpies flanker Jordan Dwight got a turnover the and men from Bathgate Park wriggled out of a very tight spot.
Taieri had been clinical all season but that was a blown opportunity.
The Eels got back in front with a fifth penalty with 10 minutes remaining.
