Key Moments
The Red Devils' disappointing run of form continued at Leeds' fortress, but manager the Portuguese tactician had Matheus Cunha to thank for his side avoiding even more damage against Leeds.
The Everton loanee headed a first-period effort against the woodwork for the in-form home team before the American midfielder finished superbly with a low, 62nd-minute effort.
At that stage, Amorim was under intense scrutiny after his side had failed to beat struggling Wolves at home earlier in the week.
Nevertheless, against opponents who had less time to prepare, the forward levelled three minutes after the opener when he ran on to a pass from substitute the Dutchman and slid a finish underneath advancing Leeds goalkeeper Lucas Perri.
It was only the South American's fourth goal since his high-profile summer move and came at a time when Amorim 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 full length save out of Manchester United goalkeeper Senne Lammens with a audacious overhead kick, and visiting heads were in hands when Benjamin Sesko, who is struggling to make an impression, turned his teammate's cut-back wide from six yards out.
The goalscorer, who had a goal disallowed for offside much earlier in the contest, also fired against a post late on.
The draw prolongs Leeds' unbeaten run to seven matches, their longest such streak since 2001, and takes them eight points clear of the relegation zone.
For the visitors though, it was yet another chance to move into the Champions League places, 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 participating nations make a swift exit.
Current injuries to skipper Bruno Fernandes and England international Mason Mount only exacerbated the impact the absence of other attackers is having on the team's squad.
It's not that the absent players are the solution to all of United's problems. After all, they were part of the side that suffered poor results earlier in the campaign.
But without them, the boss has limited alternatives in attack.
He evidently does not trust teenager Shea Lacey or the seasoned Joshua Zirkzee, even though the Dutch forward provided the assist for the equaliser almost instantly after his arrival as a replacement.
That leaves Cunha, who has now scored three goals in recent outings, and others operating out of their natural positions, alongside Benjamin Sesko.
On this evidence, the expensive frontman looks no better than previous underwhelming signings, lacking in belief and assurance in front of goal.
His failure to turn home the cross means it is now a long run without a goal for the new signing.
After thrilling victories in their last few home games, the arrival of their fiercest rivals to Elland Road was a comparatively subdued affair.
True, there were instances of typical atmosphere, but the hostile edge was not as evident as in other fixtures.
The home fans were more concerned about their side's struggle to get worthwhile possession in dangerous areas for any length of time.
The Calvert-Lewin header that struck the post was an isolated moment of threat in a congested first half.
It still felt as though Leeds were struggling when a defensive error opened the door for Aaronson.
For a short moment, Leeds' ecstatic fans thought they were about to secure a rare win against Manchester United.
Nevertheless, there is a wider context for Daniel Farke and the club to deal with.
When they suffered a poor run of form earlier in the season, many speculated about the manager's future.
Instead, he is now masterminding clear improvement.
The job is not completed yet but gradually, the team are getting nearer to achieving their survival.
Leeds have a top-flight trip to Newcastle in midweek, followed by the start of their FA Cup campaign next weekend. The Red Devils face a league trip to Turf Moor before also entering their FA Cup journey with a home tie.
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