Match Summary
The Red Devils' poor run of form persisted at Leeds' fortress, but head coach the Portuguese tactician had his Brazilian forward to thank for the team avoiding even more disappointment against their old rivals.
Dominic Calvert-Lewin directed a first-half effort against the post for the confident home team before Brenden Aaronson applied a cool finish with a low, 62nd-minute shot.
At that stage, Amorim was under intense scrutiny after his side had been held by struggling Wolves at Old Trafford earlier in the week.
However, against a team who had two days less to prepare, the forward levelled three minutes after the opener when he latched onto a through ball from substitute Joshua Zirkzee and guided a shot underneath advancing Leeds goalkeeper Lucas Perri.
It was only the South American's fourth goal since his big-money summer move and came at a time when Amorim is without four key attacking players due to a mix of fitness issues and international duty.
Not that the hosts to care about that given their own tight schedule.
Noah Okafor forced a diving save out of Manchester United goalkeeper Senne Lammens with a audacious overhead kick, and United heads were in hands when the Slovenian striker, who is struggling to make an impact, turned his teammate's cut-back wide from close range.
The goalscorer, who had a goal disallowed for offside much earlier in the contest, also blasted against a post late on.
The draw extends the home side's unbeaten run to seven matches, their best such streak since over two decades ago, and takes them a significant margin clear of the drop zone.
For the Manchester United though, it was yet another chance to move into fourth spot, albeit only for a matter of hours, wasted.
With the AFCON reaching its knockout phase, Amorim could be forgiven for hoping the participating nations make a pretty quick exit.
Current injuries to skipper Bruno Fernandes and Three Lions star Mason Mount only exacerbated the impact the unavailability of other forwards is having on the team's squad.
It's not that the missing pair 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 few attacking options.
He evidently does not trust youngster Shea Lacey or the seasoned Zirkzee, even though the Netherlands forward provided the through ball for the equaliser almost instantly after his introduction as a substitute.
That leaves the Brazilian, who has now scored three goals in five games, and others playing out of their preferred positions, alongside Sesko.
On this showing, the expensive frontman looks no better than previous underwhelming signings, lacking in confidence and conviction in front of goal.
His failure to turn home Zirkzee's cross means it is now a long run without a goal for the young striker.
After thrilling victories in their previous home games, the arrival of their fiercest rivals to Elland Road was a bit drab affair.
True, there were moments of typical atmosphere, but the hostile edge was not as pronounced as in previous fixtures.
Leeds' fans were more preoccupied about their side's inability to get worthwhile possession in advanced areas for any length of time.
The striker's header that clipped the post was an rare moment of threat in a tight first half.
It still felt as though Leeds were struggling when a defensive error opened the door for the opener.
Ever so briefly, Leeds' ecstatic fans thought they were about to secure a coveted win against Manchester United.
Nevertheless, there is a wider context for the manager and Leeds to deal with.
When they endured a poor run of form earlier in the campaign, many thought about the manager's future.
In contrast, he is now overseeing clear improvement.
The task is not completed yet but gradually, the team are getting nearer to securing their top-flight status.
The Yorkshire club have a top-flight trip to St James' Park 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 beginning their FA Cup journey with a Old Trafford tie.
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