A game that was low on quality but high on drama sparked into life in the second half when Thierry Gale put the Whites ahead, only for Theo Archibald to equalise three minutes later.
The points hung in the balance until the bitter end when a handball from Azeem Abdulai gave sub Burstow the chance to win the game, and end his own wait for a goal that stretched back to the win against Peterborough in October.
Wanderers made three changes to the side that drew against Stevenage, bringing John McAtee back for his first league start since the opening weekend of the season.
Ethan Erhahon and Gale replaced Mason Burstow and Josh Sheehan, who had picked up a calf injury in the build up to the game.
The first half was a frustrating affair, Bolton’s sloppiness in possession highlighting Sheehan’s absence and an injury to Amario Cozier-Duberry midway through potentially leaving Schumacher with something else to think about in the final week of the transfer window.
A miskick from Leyton Orient keeper Killian Cahill set the tone, once which bounced fortuitously off McAtee’s head but without the pace needed to beat the keeper back to an unguarded goal.
Shanked clearances from Jack Bonham, Eoin Toal and Ethan Erhahon put the Whites under unnecessary pressure and the visitors nearly snatched a lead when a slow reaction to a quick throw left Archibald clear on the left but Demetri Mitchell failed to connect properly with his far-post cross.
The errors kept on racking up and Jordi Osei-Tutu went into the referee’s book when he chased back to foul Archibald just outside the penalty box. Moments later, a crunching challenge from Jack Simpson on the halfway line was not penalised and eventually left Cozier-Duberry needing to leave the field injured.
Gale had Bolton’s first meaningful shot on goal half an hour in and before half time he and Conway manufactured another good chance, with the latter getting his footing wrong to skew his shot wide.
Osei-Tutu also brought a save out Cahill after a quick counter attack but the O’s continued to feed off Bolton’s mistakes on the ball and they nearly grabbed the lead in stoppage time when Kaelen Casey connected with Ollie O’Neill’s cross but could not test Bonham.
Disgruntled home fans were cheered up 29 seconds into the second half when Gale stepped in from McAtee’s pass to drive in his sixth goal of the season.
That change of mood only lasted a few minutes, though, and after Erhahon had been caught on the ball, Mitchell drove forward to cross for captain Archibald to finish well from eight yards.
Bonham nearly played himself into trouble moments later, his clearance landing nicely for O’s top scorer Dom Ballard. The Bolton keeper was able to claim the ball on the edge of the box but with visiting boss Richie Wellens vehemently claiming a penalty – protests that eventually landed him a yellow card.
Another poor ball from Conway led to Tyreeq Bakinson breaking into the penalty box on the hour, his right-footed shot slamming into the side netting.
Wanderers were being given chances, though, with Gale having one effort deflected wide and Dalby narrowly failing to turn a shot at goal from the far post from Cyrus Christie’s delivery on the left.
Gale went down injured with 20 minutes left and had to be replaced – another worry for Schumacher on the fitness front ahead of Tuesday’s game against Burton.
Sub Aaron Morley produced a superb cross to pick out Chris Forino, who couldn’t get his footing right to get a decent shot on goal from close range. At the other end, Leyton Orient laid siege to the Bolton goal for a full 60 seconds with Forino making one vital clearance in front of goal as they struggled to clear the pressure.
It was hard to pick a winner but Bolton had been given enough chances for them not to give up hope it could be them. And then in the 90th minute, something quite unexpected happened.
For the first time in the league this season the Whites were awarded a penalty. Morley’s cross from the left was handballed by Azeem Abdulai and as 10 minutes of stoppage time was shown by the fourth official, Burstow – only a few minutes after entering the game as a sub – claimed the ball and put it on the spot.
Without a goal since October, a run which stretched over 19 hours on the pitch, he blasted his penalty down the middle to finally move on to eight for the season.
Of course, there was still room for drama. Ref Seb Stocksbridge made a puzzling reversal of an indirect free kick decision made against O’s keeper Cahill for a pass-back, which had the Toughsheet reverberating with jeers.
It was all hands to the pump at the end but, maybe for the first time in the whole afternoon, there was a sense of calm about Bolton as they saw the game out professionally to claim an important win.