Wingers Rob Smyth and Dominic Peters, both preferred to Martin Offiah in the London line-up, were the guilty men as a winning position was transformed into a losing one in eight nightmare second half minutes.
Smyth started the rot by knocking on to give Wigan scrum possession from which to score their first try in over two hours through Danny Moore. Then it was Peters' turn, losing kicks from Kris Radlinski and Greg Florimo to give Wes Davies and Mark Reber the tries that put Wigan in front.
That came after London had dominated the first half to an extent that was not reflected in a modest 12 point lead. They caught a Wigan lacking the guiding influence of Andy Farrell and Gary Connolly unawares early on, Karle Hammond and Glen Air moving the ball on the last tackle for Mat Toshack to go through a hesitant defence. Smyth added the conversion against his old club, but missed a much easier penalty that would have put Wigan deeper in trouble.
The creative Hammond worked a couple of other promising openings that could have paid off before London scored their second try after 27 minutes. John Timu was the architect of this one, kicking ahead and chasing the bouncing ball, which sat up conveniently off a Wigan hand for Dean Callaway to be awarded the try after video scrutiny.
Smyth was again on target and the only signs of Wigan waking up came with one run by Mick Cassidy from Jason Robinson's pass and a clever kick from Davies that almost fell for Tony Smith.
That apart, it was the home team with all the ideas. London wasted a couple of opportunities for a valuable drop goal before they began their comedy of errors. They tried manfully to repair the damage after that, but the harm was done. In the last 10 minutes Wigan added further tries from Smith and Jon Clarke to mock their earlier inadequacies.
"We were lucky to get out of it," Wigan's coach, John Monie, admitted.
London still have not won since before Wembley, but Dan Staines insisted: "I thought we showed enough to show that we are going to stake a claim this year. Accidents happen, but I don't blame those players at all."
London Broncos: Fleming, Smyth, Ryan, Timu, Peters, Air, Hammond, Millard, Beazley, Cram, Retchless, Wynward, Toshack. Substitutes used: Gill, Callaway, Spencer, Seibold.
Wigan Warriors: Radlinski, Davies, Moore, Florimo, Jones, Robinson, Smith, Cowie, Clarke, Mestrov, Betts, Haughton, Cassidy. Substitutes used: Reber, O'Connor, Gilmour, Bretherton.
Referee: S Ganson (St Helen's).Reuse content