Alex Baptiste's left-footed strike saw Wanderers hit-back before half-time and Ngog fired home the second at the end of regular time to seal a point in what has been a difficult week off the field.
The Trotters announced that they were in over B£130million of debt after their relegation from the Premier League two years ago.
Shay Given started in goal for Boro after the former Republic of Ireland international extended his loan from parent club Aston Villa for a further two months. Dougie Freedman selected Joe Mason up front in what was due to be the Cardiff forward's last game before he goes back to South Wales.
The visitors were creating the early inroads and just nine minutes in took the lead.
A defensive error from Knight saw the Bolton centre-half lose the ball at his feet when trying to play the ball out from the back. The impressive Carayol then took full advantage and beautifully fired the ball past Lonergan into the top right corner of the net from 20 yards.
Wanderers almost equalised on the counter, with Chris Eagles' half volley from inside the box just going wide.
But, just as the Trotters were looking to get back into the game, things went from bad to worse for Knight.
This time the former England international's pass back to Lonergan was wildly over hit. That gave Main a free tap in on the line to double Middlesbrough's lead, with deafening jeers now directed at Knight with his every touch of the ball.
Bolton then cut the deficit back to one goal shortly after as Baptiste curled his shot from just inside the penalty area past a helpless Given.
A poor pass out by the Boro stopper then should of resulted in Wanderers grabbing an equaliser before half-time. Indecisive play made sure that was not the case, though, with Chung-Yong Lee's poor effort blocked before Jay Spearing blazed the ball over the bar.
The Trotters came out for the second half the more motivated and the crowd thought that they had the leveller when Mark Davies's found Mason in the box. However, Mason's strike was fired into the side netting instead of the back of the net.
Despite a strong Boro rear-guard action, the vital second inevitably arrived cruelly in the 90th minute as substitute Ngog rifled his shot past Given to ensure Bolton shared the points.
- Sports & Recreation
- Andy Lonergan
- Alex Baptiste
- Mustapha Carayol
- Joe Mason