Mark and Paul Cummins had got United’s innings off to a disastrous start as they were both removed by Dominic Sharp with only two runs on the board. Ben Percival didn’t fare much better with just three and once again it was Sharp who bowled him out.
However, Tetley stepped up to the crease and hit 78 to put United back in the match. A Dean Smith 40 later on was also instrumental in the victory as they went on to score 186.
Fortunately for United, Mark and Paul Cummins were in good bowling form and they took seven wickets between them for just 91 runs from 28.1 overs as Castleford struggled to score and they were all out for 155 and United took all eight points from the fixture.
Rotherham, whose game against league leading Cleethorpes was reduced to 35 overs, battled to an incomplete win.
Gurman Randhawa hit five fours on his way to a score of 42 from 64 balls and big-hitting Jordan Lowe chipped in with three sixes and two fours on his way to 42 from just 33 balls.
Bill Kirby’s 46 got Cleethorpes off to a good start as they chased Rotherham’s score of 165 but Ben Sanderson took four for 43 to see them score 150 and Rotherham left with six points.
Barnsley moved level on points with Cleethorpes at the top of the league after they won by eight runs against Driffield.
Steven Nuttall scored 63 to help Barnsley hit 165, and with rain delaying the start, the match was restricted to 45 overs.
Ryan Hercules took three for 49 from 11.4 overs and Driffield were all out for 157, although 60 from Ben Kohler-Cadmore did give them a scare.
Doncaster v Scarborough and Sheffield Colv Hull were both rained off.