Match Summary
The Red Devils' disappointing recent struggles persisted at Leeds' fortress, but manager Ruben Amorim had his Brazilian forward to thank for the team avoiding even more damage against their old rivals.
Dominic Calvert-Lewin directed a first-half effort against the woodwork for the in-form home team before Brenden Aaronson finished superbly with a low, 62nd-minute effort.
With the goal, Amorim was under intense scrutiny after his side had been held by bottom-of-the-table Wolverhampton Wanderers at home earlier in the week.
Nevertheless, against a team who had less time to prepare, the forward levelled three minutes later when he ran on to a pass from introduced Joshua Zirkzee and slid a shot underneath rushing Leeds goalkeeper Lucas Perri.
It was only the South American's fourth Premier League goal since his big-money summer move and came at a time when the manager is without four key attacking players due to a combination of fitness issues and national team commitments.
Not that you would expect the hosts to care about that given their own lack of preparation time.
Noah Okafor forced a diving save out of visiting goalkeeper Senne Lammens with a spectacular overhead kick, and visiting heads were in hands when Benjamin Sesko, who is struggling to make an impact, turned his teammate's cut-back wide from close range.
Cunha, who had a goal disallowed for offside much earlier in the match, also fired against a post in the dying moments.
The point extends Leeds' unbeaten run to seven games, their best such streak since over two decades ago, and takes them eight points clear of the relegation zone.
For the visitors though, it was yet another opportunity to move into fourth spot, albeit only for a short time, squandered.
With the Africa Cup of Nations reaching its knockout phase, the United coach could be understood for hoping the involved countries make a swift exit.
Existing injuries to skipper Bruno Fernandes and Three Lions star Mason Mount only exacerbated the impact the unavailability of other forwards is having on Amorim's options.
It's not that the missing pair are the answer to all of United's problems. After all, they were part of the side that experienced disappointing results earlier in the campaign.
But without them, Amorim has limited alternatives in attack.
He clearly does not trust youngster Shea Lacey or the seasoned Zirkzee, even though the Dutch forward delivered the assist for Cunha's equaliser almost instantly after his introduction as a replacement.
That leaves the Brazilian, who has now scored three goals in five games, and others operating out of their preferred positions, alongside Benjamin Sesko.
On this showing, the big-money frontman looks similar to previous struggling signings, lacking in belief and conviction in front of goal.
Sesko's failure to turn home Zirkzee's cross means it is now nine games without a goal for the young striker.
After thrilling victories in their last few home games, the arrival of their fiercest rivals to Elland Road was a bit drab affair.
True, there were moments of expected atmosphere, but the hostile edge was not as evident as in previous encounters.
Leeds' fans were more concerned about their side's struggle to get worthwhile possession in advanced areas for any length of time.
The striker's header that struck the post was an isolated moment of quality in a congested first half.
It still felt as though the hosts were struggling when a mistake opened the door for Aaronson.
Ever so briefly, The home ecstatic fans thought they were about to secure a coveted win against Manchester United.
However, there is a wider context for the manager and Leeds to deal with.
When they suffered a difficult run of form earlier in the campaign, many speculated about the manager's position.
Instead, he is now masterminding clear progress.
The task is not completed yet but gradually, Leeds are getting nearer to securing their top-flight status.
Leeds have a top-flight trip to Newcastle in midweek, followed by the start of their domestic cup campaign next weekend. Manchester United face a Premier League trip to Turf Moor before also entering their FA Cup journey with a home tie.
Liam Sterling is a seasoned betting analyst with over a decade of experience in the online gambling industry.