Key Moments
The Red Devils' disappointing run of form continued at Elland Road, but head coach Ruben Amorim had his Brazilian forward to thank for his side not suffering even more disappointment against Leeds.
The Everton loanee 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, the United boss was under intense scrutiny after his side had failed to beat bottom-of-the-table Wolverhampton Wanderers at Old Trafford earlier in the week.
However, against opponents who had two days less to recover, Cunha restored parity three minutes later when he ran on to a through ball from substitute the Dutchman and guided a finish underneath rushing Leeds goalkeeper Lucas Perri.
It was only the Brazilian's fourth goal since his high-profile summer move and came at a time when the manager is without four key attacking players due to a mix of fitness issues and international duty.
Not that you would expect the hosts to sympathise with that given their own tight schedule.
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 the Slovenian striker, who is finding it hard to make an impact, turned Zirkzee's cut-back wide from six yards out.
The goalscorer, who had a goal ruled out for offside much earlier in the match, also fired against a post late on.
The draw extends the home side's unbeaten run to seven games, their longest such streak since 2001, and takes them a significant margin clear of the drop zone.
For the Manchester United though, it was yet another opportunity to move into the Champions League places, albeit only for a short time, squandered.
With the AFCON reaching its knockout phase, Amorim could be forgiven for hoping the involved countries make a pretty quick exit.
Existing injuries to skipper Bruno Fernandes and England international Mason Mount only heightened the impact the unavailability of other attackers is having on the team'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 experienced disappointing results earlier in the season.
But without them, the boss has limited attacking options.
He clearly does not trust youngster Shea Lacey or the seasoned Zirkzee, even though the Dutch forward provided the assist for Cunha's equaliser almost immediately after his arrival as a replacement.
That leaves Cunha, who has now scored a small tally in recent outings, and others playing out of their natural positions, alongside Benjamin Sesko.
On this showing, the expensive frontman looks similar to previous struggling signings, lacking in belief and conviction in front of goal.
His failure to turn home the 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 home was a comparatively subdued affair.
True, there were instances of expected atmosphere, but the hostile edge was not as pronounced as in previous encounters.
Leeds' fans were more concerned about their side's inability to get sustained possession in advanced areas for any length of time.
The striker's header that clipped the post was an isolated moment of quality in a tight first half.
It still felt as though the hosts were struggling when a defensive error opened the door for Aaronson.
Ever so briefly, The home delirious 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 suffered a difficult run of form earlier in the season, many thought about the manager's future.
In contrast, he is now masterminding clear progress.
The task is not done yet but step by step, Leeds are getting closer to securing their survival.
The Yorkshire club have a top-flight trip to St James' Park in midweek, followed by the start of their domestic cup campaign next weekend. Manchester United face a league trip to Burnley before also beginning their cup journey with a Old Trafford tie.