Whitehaven won a close game 19-12 at Hunslet to go four points clear at the top of League One.
They drew first blood after nine minutes as Jordan Burns scored a penalty after nine minutes.
But two penalties from Reece Dean meant the South Leeds side led at the break.
Burns added another penalty early on to level the scores, but they did not stay level for long.
Hunslet edged back ahead just three minutes later as Nathan Chappell grabbed the first try of the game. Dean converted to put the South Leeds side ahead by six points.
From there, however Whitehaven clawed their back into the game as Ethan Kelly grabbed a try. Burns then converted to level the scores.
Haven then grabbed the lead for the first time since the half hour mark as Connor Holiday added a penalty to make it 14-12.
Then the leaders grabbed the game clinching try as David Thompson scored with just ten minutes to go. The conversion was missed this time, meaning they were just one converted try ahead.
But Haven were able to see the game out as Holiday grabbed a drop goal with the clock winding down.
That result means the Cumbrians have extended their lead at the top of League One, though they have played a game more than the Thunder. They welcome Cumbrian rivals Workington Town next Sunday, as they look to edge closer to confirming top spot.
As for Hunslet, that result leaves them fifth in League One but they are still safe in the playoffs for now. They will hope to bounce back when they welcome North Wales Crusaders next Sunday.