Match Summary
Manchester United's disappointing run of form continued at Leeds' fortress, but head coach the Portuguese tactician had his Brazilian forward to thank for the team avoiding even more damage against Leeds.
Dominic Calvert-Lewin headed a first-period attempt against the post for the in-form hosts before the American midfielder applied a cool finish with a driven, 62nd-minute shot.
At that stage, Amorim was under intense scrutiny after his side had failed to beat bottom-of-the-table Wolves at home earlier in the week.
Nevertheless, against opponents who had less time to recover, Cunha restored parity three minutes after the opener when he ran on to a pass from introduced Joshua Zirkzee and guided a shot underneath advancing home goalkeeper Lucas Perri.
It was only the Brazilian's fourth Premier League goal since his high-profile summer move and came at a time when the manager is without four key attacking players due to a combination of injury and international duty.
Not that the hosts to care about that given their own lack of preparation time.
Noah Okafor forced a diving save out of Manchester United goalkeeper Senne Lammens with a spectacular overhead kick, and United heads were in hands when Benjamin Sesko, who is finding it hard 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 contest, also blasted against a post in the dying moments.
The draw prolongs the home side's unbeaten run to seven games, their best such streak since over two decades ago, and takes them eight points clear of the drop zone.
For the visitors though, it was yet another opportunity to move into fourth spot, albeit only for a short time, wasted.
With the AFCON reaching its latter stages, Amorim could be understood for hoping the participating nations make a swift exit.
Existing injuries to captain Bruno Fernandes and Three Lions star Mason Mount only heightened the impact the unavailability of other forwards is having on Amorim's squad.
It's not that the absent players are the answer 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 attacking options.
He evidently does not trust youngster Shea Lacey or the much more experienced Joshua Zirkzee, even though the Netherlands forward provided the assist for the equaliser almost instantly after his introduction as a replacement.
That leaves Cunha, who has now scored three goals in five games, and others operating out of their preferred positions, alongside Benjamin Sesko.
On this evidence, the big-money frontman looks no better than previous underwhelming signings, lacking in belief and assurance in front of goal.
Sesko's failure to turn home the 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 comparatively subdued affair.
True, there were instances of expected fervor, but the intimidating edge was not as pronounced as in previous fixtures.
The home fans were more preoccupied about their side's struggle to get worthwhile possession in dangerous areas for any prolonged period.
The striker's header that clipped the post was an rare moment of quality in a tight first half.
It still felt as though the hosts were finding it tough when a mistake opened the door for Aaronson.
Ever so briefly, Leeds' delirious fans thought they were about to secure a coveted win against Manchester United.
Nevertheless, there is a much bigger picture for the manager and the club to deal with.
When they suffered a difficult run of form earlier in the season, many speculated about the manager's position.
In contrast, he is now masterminding significant progress.
The job is not completed yet but step by step, Leeds are getting nearer to securing their survival.
Leeds have a top-flight trip to St James' Park in midweek, followed by the start of their FA Cup campaign next weekend. Manchester United face a league trip to Burnley before also beginning their FA Cup journey with a home tie.
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