At a Glance
The Red Devils' poor run of form continued at Leeds' fortress, but head coach the Portuguese tactician had his Brazilian forward to thank for his side not suffering even more damage against their old rivals.
Dominic Calvert-Lewin headed a first-period attempt against the post for the confident hosts before Brenden Aaronson applied a cool finish with a driven, 62nd-minute shot.
With the goal, the United boss was in the firing line after his side had been held by bottom-of-the-table Wolverhampton Wanderers at Old Trafford earlier in the week.
However, against a team who had less time to recover, Cunha restored parity three minutes later when he latched onto a pass from substitute Joshua Zirkzee and guided a finish underneath rushing Leeds 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 several key attacking players due to a combination of fitness issues and international duty.
Not that Leeds to care about that given their own lack of preparation time.
The Swiss attacker forced a full length save out of Manchester United goalkeeper Senne Lammens with a audacious overhead kick, and United heads were in hands when Benjamin Sesko, who is struggling to make an impact, turned Zirkzee's cut-back wide from close range.
Cunha, who had a goal ruled out for offside much earlier in the match, also fired against a post in the dying moments.
The draw prolongs Leeds' 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 opportunity to move into fourth spot, albeit only for a short time, squandered.
With the AFCON 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 squad.
It's not that the absent players are the solution to all of the club's problems. After all, they were part of the side that suffered disappointing results earlier in the season.
But without them, the boss has few attacking options.
He clearly does not trust teenager Shea Lacey or the much more experienced Zirkzee, even though the Dutch forward delivered the through ball for Cunha's equaliser almost immediately after his introduction as a replacement.
That leaves the Brazilian, who has now scored three goals in recent outings, and others operating out of their preferred positions, alongside Sesko.
On this showing, the big-money frontman looks similar to previous struggling signings, lacking in confidence and conviction in front of goal.
Sesko's failure to turn home the cross means it is now nine games without a goal for the new signing.
After thrilling victories in their previous home games, the arrival of their biggest rivals to home was a comparatively subdued affair.
True, there were instances of typical atmosphere, but the hostile edge was not as pronounced as in other encounters.
The home fans were more concerned about their side's struggle to get sustained possession in advanced areas for any length of time.
The striker's header that struck the post was an rare moment of quality in a tight first half.
It still felt as though Leeds were struggling when a mistake opened the door for Aaronson.
For a short moment, Leeds' ecstatic fans thought they were about to secure a rare win against their old foes.
However, there is a wider context for the manager and Leeds to deal with.
When they endured a difficult run of form earlier in the campaign, many speculated about the manager's position.
In contrast, he is now overseeing clear improvement.
The task is not completed yet but gradually, the team are getting closer to achieving 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. Manchester United face a league trip to Burnley before also entering their cup journey with a home tie.
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