Daryl Powell ranked under-strength Castleford's 16-12 victory over St Helens as one of the best of his career.
The Tigers coach used the game as an opportunity to examine his fringe players after opting to rest four starmen following the second double-header of the season last weekend.
Zak Hardaker, Luke Gale, Michael Shenton and Grant Millington all watched on from the sidelines as Castleford overturned a 12-4 deficit and overcame the loss of key forwards Jesse Sene-Lefao and Junior Moors - to head injuries - to record a significant win.
The Tigers had averaged 48 points across their eight straight home victories in 2017 but, with their squad stretched, they proved they have the depth to mount a sustained challenge for the Super League title.
"It's one of the biggest wins I've been involved in," said Powell, who represented Great Britain as a player.
"For a team that had been played about with to roll into a game against opposition that had a significant rest period on us and a full-strength team and come out with that kind of performance was awesome.
"We had to dig in right at the end and the amount of scrambled tackles to keep them out shows the character we've got.
"What we've become as a club is we've got genuine depth and belief that we've got something special here."
Leading up to the game Powell was angry that his side had to back up after playing two matches in four days over the Spring Bank Holiday weekend while Saints were fresh from a 10-day turnaround after their scheduled fixture at Huddersfield on Monday was rearranged.
Powell admitted it was a gamble to make wholesale changes but it was one that paid off as tries from debutant Kieran Gill, Mike McMeeken and Tom Holmes moved Castleford four points clear at the top of the table.
"I've just said to the conditioner and the physio that they're off the hook," added Powell.
"They were pretty relieved we came up with that today because they've been drivers in looking after the boys. There's only so much you can put the players through.
"It was a risk but we've been able to come out of it in a positive way. I'm not sure I expected it to be that positive but I'm massively pleased it was."
Saints were on course for a third-straight win under Justin Holbrook after tries from Mark Percival and Louie McCarthy-Scarsbrook gave them a half-time lead.
But they were kept scoreless in the second half to leave their new coach frustrated.
"We knew it was going to be a tough game and it would have been great to win," said Holbrook. "To fall just short is very disappointing.
"Castleford obviously weren't at full strength but they haven't lost here for a reason. They're a very good footy side and they showed that again today.
"But it was a missed opportunity. They had the luxury to rest a few today because of where they are sitting in the table and they earned that.
"For us to fall just short, it's really costly for where we're sitting in the table.
"It was disappointing we didn't get the win but I'm really happy with the squad and we came really close today. It's important we just move on to next