The Cougars romped into a 38-0 first-half lead at struggling Gateshead Thunder and looked to be on their way to a big win before the home side struck back to edge a scrappy second half by four points.
It was an error-strewn second period from the Cougars who ran in seven first-half tries but managed only one – from James Feather – late in the second half
Ollie Pursglove grabbed a brace, Keighley scoring from their first set through the second row after Steve Coutts had knocked on from the kick-off.
The first half was plain sailing for Demetriou’s men as touchdowns from Richard Jones, James Hutchinson and Dan Belcher kept Gateshead firmly on the back foot.
Keighley bossed possession and field position and Chris Baines’s crossfield angled run exposed more suspect home defence.
Pursglove cut through weak defence to stretch the lead and Will Cartledge powered over in the tackle to put the seal on a solid first-half display.
Gateshead tightened up after the break as the Cougars ball retention suffered and pulled a try back on the hour when quick hands put Micky Ward over.
Keighley’s frustrations were becoming evident and Thunder grabbed a second when Tom Hodgson put Joe Brown over.
Their only try of a disappointing second half came nine minutes from time when Feather hit the line from dummy half.
“We were awesome first half but not very good in the second half,” said Demetriou. “In the first half we completed well and worked the systems the way we’re supposed but in the second half, we played as individuals.”
Gateshead Thunder: Condron, Olugbode, Morris, Harding, Brown, Clarke, Coutts, Payne, Hodgson, Parker, Stoker, Ward, Bate. Substitutes: Brandt, Young, Norman, Sargeant
Keighley Cougars: Belcher, Duffy, Sagar, Baines, Hutchinson, Drake, Smith, Shickell, Feather, Jones, Pursglove, Shepherd, Haythornthwaite. Substitutes: Wray, Barr, Benjafield, Cartledge
Referee: C Leatherbarrow (RFL).