St Helens came from behind to end Castleford’s unbeaten run and leave the Tigers still looking for a first away win over them since 1992.
The visitors led 8-0 and 14-6 in a thrill-a-minute first half at Langtree Park, but crucially lost stand-off Ben Roberts with a leg injury after 23 minutes, while influential prop Grant Millington went off on the hour with a hand problem.
Centre Matty Dawson, deputising for the injured Mark Percival, scored two of Saints' five tries in the 28-22 victory as they made it three wins from their opening four games to close to within two points of leaders Widnes Vikings.
St Helens dominated the first half, with hooker James Roby causing havoc around the ruck and skipper Jon Wilkin and scrum-half Luke Walsh forcing six goal-line drop-outs between them, but the Tigers tackled furiously to keep themselves in the game and looked threatening on the counter-attack.
Trailing 16-14 at the break, Castleford ought to have made more of a clean break by full-back Luke Dorn but they drew level with a Ben Crooks penalty nine minutes into the second half.
That was as good as it got for the Yorkshiremen, however, as they continued to spend most of the game pinned inside their own half.
Castleford were left counting the cost of defeat after losing three key players to injury.
Stand-off Roberts went off with a foot injury after 23 minutes which left the Tigers a playmaker short, and they also lost forwards Millington and Junior Moors in the second half
"There are a lot of injuries around in Super League at the moment and we've picked up three which could be really costly," said coach Daryl Powell. "They are key players for us.
"Obviously it's very difficult when you lose a half-back who is on top of his game.
“We had just scored a try and I thought we were on top at that point. We were down to one sub for the last 30 minutes which is tough."
