Wigan coach Shaun Wane was relieved to see his side avoid a potential banana skin as they began their defence of the Tetley's Challenge Cup with a 58-6 victory at part-timers Dewsbury.
The holders made a bright start to the fourth-round tie with two tries in the first nine minutes from teenage winger Joe Burgess, but they were kept scoreless for the next 39 and led only 12-6 after winger Dale Morton scored for the Championship side early in the second half.
But Super League champions Wigan eventually found their rhythm and took full advantage of a tiring defence to run in 30 points in the last 17 minutes, with Burgess taking his tally to four tries.
"It was never going to be an easy ride in the first half," Wane said. "It was their cup final and they've got some good players and they're well coached.
"It's a small pitch and an inexperienced referee, so with all that combined we knew it was going to be tough.
"On the back of that, our completion in the first half was poor at 51 per cent and in the second half we were at 94 per cent so that tells you everything."
Centre Iain Thornley scored two tries and others came from Dan Sarginson, Matty Smith and George Williams.
The only disappointment for the holders was an injury to England winger Josh Charnley, who left the Tetley's Stadium on crutches and looks set to miss the Good Friday derby at St Helens.
"He's hyper-extended his knee," Wane said. "We'll have him scanned tomorrow and there's a chance he might only be a couple of weeks."
Dewsbury coach Glenn Morrison was full of pride for his part-time players, who included postmen, labourers and a lifeguard.
"Some of the boys have been up since five o'clock working and had to come straight to the game," Morrison said.
"We were always going to find it tough near the end and we just ran out of juice.
"But for 60 minutes we went toe to toe with the champions. We looked good for a lot of that period.
"Obviously the last 20 minutes was disappointing but we only had one sub on the bench."
Among the injury victims was young half-back Aaron Brown, who went off in the early stages with damaged knee ligaments.
"That was a shame," Morrison said. "He's a good kid and it would have been good to see him play in a game like that because he's destined for Super League."