Leigh were 14-2 ahead at Hull KR in a game that seemed to have survived the swirling fog when a floodlight failure forced it to be abandoned after 52 minutes.
"The light was very bad at ground level and players' safety is paramount," said the referee, Stuart Cummings, who ruled that conditions were still not fit for play even when some of the lights came back on after a 15-minute break.
Leigh had led through first-half tries from Chris Irwin and Jon Roper, but will now have to travel to Humberside to replay the match. That left the Leigh coach, Paul Terzis, furious. "It was sheer incompetence," he said. "None of our players complained and we wanted to finish the match."
The abandonment means Huddersfield take sole possession of top spot, but only by a point after Chris Thorman missed two late drop-goal attempts to sink Whitehaven.
The Warriors fought their way back from a 12-0 half-time deficit to tie the game with converted tries from David Seeds and Aaron Lester. Steve Kirkbride could have settled the game in the home side's favour but was also wayward with a one-pointer. Scores from Hefin O'Hare and Paul March either side of two Thorman penalties, had seen the Giants take a comfortable lead.
Haven were overtaken by their Cumbrian rivals Barrow, who overcame Gateshead 22-14 for their fourth consecutive win.
Andy Kelly's side made life difficult for the Raiders for over an hour before a superb individual try from Shane Irabor broke their resistance.
Andy Henderson had put Barrow ahead with an eighth-minute try before the same player's pass was intercepted by Thunder's Scott Dyson for a 40-metre score. Barrow twice edged back in front through Darren Holt and Steve Jackson but Dyson's second try and a further touchdown from Kevin Neighbour kept Gateshead in the game until Irabor settled matters.
Oldham enjoyed a change of fortune as they began life without their former coach, Mike Ford, by securing their first win at the third attempt. The Roughyeds ran out 32-16 winners over bottom-side York in their first home fixture since last May. The winger Joe McNicholas ran in two tries with Bryan Henare, Phil Farrell, John Hough and Neil Roden also crossing the line.
Featherstone also secured their first home win of the season as late Chris Spurr and Gavin Swinson touchdowns saw them beat Sheffield 28-18.
Batley's encouraging start to the season continued as the Bulldogs ran out 18-10 winners over Workington. Second-half tries from Steve McGrady and Gary Charlton brought Town back into the game before Glen Tomlinson went over to snatch the points for the Bulldogs.