A Diarmiud O'Carroll header proved enough to give Crusaders the victory which sees them take over from Linfield at the top of the Irish Premiership.
The ex-Cliftonville man met a Billy Joe Burns ball in the 47th minute for the goal which sees the Crues lead the table on goal difference.
Crusaders thought they had gone 2-0 up when Josh Robinson headed in but it was disallowed for offside.
Jordan Owens should have got the second but lifted the ball on to the crossbar.
It was a fifth successive defeat for Warrenpoint who remain four points adrift at the bottom of the league table.
What they said
Crusaders scorer Diamiud O'Carroll: "We won't be saving the DVD of this match but the three points are what matters. It's a clean sheet and we have taken over at he top of the table so we are happy with that.
"We were poor in the first half and improved a bit in the second.
"It is nice to be up at the top again. We had a bumpy start to the season but have had some good results against rivals around us."