Wanderers slumped to a derby defeat against Wigan Athletic to leave themselves in real relegation danger.
Goals from Gary Caldwell and James McArtur leave Owen Coyle's side just a point off the Latics, who still prop up the Premier League table.
After a bright start to the first half, in which Caldwell had come within inches of stabbing the ball past his own keeper to give Wanderers the lead, Wigan gradually wrestled control of the game.
Victor Moses drilled a shot into the near post, Fabio Di Santo whistled an effort just over the bar and Adam Bogdan was forced into a good save at his near post from Emerson Boyce's cross-shot.
Three minutes from the interval the Latics got a deserved lead as Caldwell leapt above David Wheater to head Jean Beausejour's corner past Bogdan for only his second of the season.
It was at that point the stewards at the Reebok were forced to wade into the away support after flares were set off behind the goal, and certainly not the last time in the afternoon.
Owen Coyle stuck to his 4-4-2 system in the second half, bringing on Ryo Miyaichi for his debut and withdrawing Martin Petrov.
But the change didn't affect the game immediately and both Boyce and James McArthur had clear sights of goal to double the lead for the visitors.
And the equaliser arrived like a bolt from the blue – with Bogdan's long punt knocked down by Ngog, and rifled into the top corner by Mark Davies.
From there, Wanderers looked the more likely side to snatch a vital three points. But instead, somke comedic defending allowed McArthur to atone for his earlier miss.
Gretar Steinsson and Zat Knight climbed for the same ball, which slithered out to Moses. The winger turned Ricketts and brought a save out of Bogdan, but McArthur was there to mop up and send the Wigan fans into delirium.
Even then, the Whites might have snatched a draw. Ngog found sub Miyaichi with a clever reverse pass and the Japanese youngster, on loan from Arsenal, was denied a goal on his first Premier League appearance by a world class save from Ali Al-Habsi.