One match down, plenty more to come. A reminder that Warrington's Ben Westwood draws his career to a close tonight. What a career he's had.
Tomorrow we do this all over again as Wigan take on Salford at the DW Stadium. That is sure to be a cracking encounter.
For now though, thank you for joining us.
Warrington back Jake Mamo told Sky Sports:
"Unfortunately we weren't there tonight. We put in a gallant effort and a few efforts summed up our game.
"I hope Castleford go on to do well. Losing Blake Austin is really tough. He's still struggling after his ankle injury and came back to do it for the team but it was unfortunate to lose him.
"It's a sad end to the season. We're massively disappointed."
Warrington head coach Steve Price told Sky Sports:
"Our decision making, especially around transition, wasn't where it needed to be tonight. Our middles worked extremely hard.
"We weren't good enough and we had a couple of lapses defensively.
"It's semi-final time. You have to make a change. Cas were desperate tonight and played better in those parts of the game."
Castleford prop Liam Watts told Sky Sports:
"We knew it would be a tough game. After a tough loss last week we had to turn up tonight with plenty of aggression, speed and intensity.
"We spoke all we about our defence. We forced some errors on Warrington.
"The team that keeps the ball the longest wins these games. It's been a tough and long season and the intensity has got to be up and we turned up with plenty tonight."
Castleford full-back Jordan Rankin told Sky Sports:
"I thought the boys turned up in defence. We knew it would be the small things that would get us over the line.
"There were errors in both teams and it's something we can work on and rectify next week.
"We have a lot of belief in the group. Whoever plays, we know they're capable of the job we need to do."
All over and boos ring around the Halliwell Jones Stadium as Warrington's comeback narrowly falls short as Castleford seal victory.
Cas will play the loser of tomorrow night's match between Wigan and Salford. The Wire's season is over, meanwhile.
Bryson Goodwin and Jake Mamo almost get a dramatic late try for the hosts but the latter is held up and tackled just before the turnover about a metre from the line.
After several exchanges of possession after that Stefan Ratchford penalty attempt, Warrington once again win the ball back.
But they're deep into their own half as Castleford keep them pegged back. Time is running out.
That has fallen well short and it's collected by Jordan Rankin and the home crowd are stunned into silence.
Five minutes remain.
The Wire win a penalty near to the halfway line in their own half.
Stefan Ratchford stands over it and is going for it!
Former Great Britain and Wales international on BBC Radio 5 Live Sports Extra
"We have game on here with just over 10 minutes to go.
"Warrington are so dangerous when they play off the cuff - so difficult to stop. That was a perfect set of six."
My word what a response from Warrington!
Chris Hill touches the ball over with ease as Castleford go to sleep pretty much from the restart and the Wire are allowed to take advantage.
Stefan Ratchford adds the two. What was that I was saying about 'touching distance' for Cas..?
Peter Mata'utia keeps up his form with the boot and kicks over another two points for Castleford who must be in touching distance, now.
Big chance for Warrington goes begging!
Jake Mamo flicks it over the top to Tom Lineham at the corner but he's well spun over and into touch by James Clare.
That is stunning defence from Castleford.
Ben Thaler says nein danke and it's not given. Liam Watts didn't look certain he'd crossed over from the get go, to be fair.
And we are back under way.
Just past the hour-mark now and surely another Castleford try would see this game off.
Liam Watts eventually gets the ball over for the visitors but it's sent to video referee Ben Thaler.
Great defence from Castleford as Dec Patton is well tackled by Jake Trueman as the Warrington half-back fumbles the ball.
The hosts look out of sorts since that Jordan Rankin try.Copyright: rex
There's a break in play as Tom Lineham is seen to by the Warrington physio.
He's cleared to play on. Blake Austin meanwhile, is sat on the sidelines with ice on his knee. Not a great night for Warrington for injuries so far.
Warrington's season will come to an end in just under half an hour if this carries on.
The Challenge Cup winners haven't been in form coming into this match and it's beginning to show.
That wasn't in the script! Jordan Rankin stuns the home crowd and crosses for his 10th Super League try of the season.
Peter Mata'uita puts the ball through the posts with ease for the extra two.Copyright: Rex Features
Warrington look like a totally different side since the restart and all the play has been with them in this second half.
Can they add to Jake Mamo's early try?