A drop goal from Gareth O'Brien four minutes from the end of an absorbing match saw Salford Red Devils inflict a first defeat of the season on Castleford Tigers and knock them off the top of the table.
It was O'Brien's golden-point drop goal that kept the Red Devils in Betfred Super League last October and the full-back produced another telling one-pointer to clinch a 13-12 victory at the AJ Bell Stadium.
Castleford came into the match as the form team of the season with an unbeaten record, and made a dream start as Luke Gale pounced on a mistake, chasing his own kick to touch down in the fifth minute.
The Red Devils refused to roll over however, and after some solid defending, pulled a try back before the break with Ben Murdoch-Masila breaking through.
Greg Eden had an effort ruled out for a forward pass, before Greg Minikin notched his ninth try of the campaign to put the Tigers further ahead.
However Murdoch-Masila pounced on a Zak Hardaker error to touch down before O'Brien stepped up with the boot to earn a tight win for Salford.
Daryl Powell had no complaints after seeing his side lose their 100 per cent record. He said: "We were poor. I don't think we ever really got our game together. It was our first real tight assignment and we came up short.
"I thought Salford were superb, they defended well and came up with a smart game plan. We didn't deserve to win. We tried to play the conditions way too much. It was a bit of an arm wrestle and they just edged it.
"There's quite a few lessons for us to learn. We need to move on and some players have some wising up to do.
"We were pretty unrecognisable today, although it doesn't help when you are having to move people around."
Credit where credit is due... well done Salford. Massive thanks to all the fans who travelled over, supports was awesome 👌Now we go again 🐯— Zak Hardaker (@zakhardaker1) March 19, 2017
On O'Brien's heroics, Ian Watson added: "He's stepped up to the fore but I think, for the bigger picture, the team executed everything we spoke about during in the week.
"I thought our middles were phenomenal against a pack that teams have been struggling to handle.
"All season so far we've been really good in parts and not been seeing those games off but that has set a little bit of a standard, that we can mix it with the best teams."