At a Glance
The Red Devils' disappointing run of form persisted at Elland Road, but manager the Portuguese tactician had his Brazilian forward to thank for his side not suffering even more disappointment against their old rivals.
Dominic Calvert-Lewin directed a first-period effort against the woodwork for the confident home team before the American midfielder applied a cool finish with a low, 62nd-minute effort.
With the goal, Amorim was in the firing line after his side had failed to beat struggling Wolves at Old Trafford earlier in the week.
However, against a team who had two days less to recover, Cunha levelled three minutes after the opener when he ran on to a through ball from introduced the Dutchman and guided a finish underneath rushing Leeds goalkeeper Lucas Perri.
It was only the Brazilian's fourth Premier League goal since his big-money summer move and came at a time when the manager is without several key attacking players due to a mix of fitness issues and international duty.
Not that Leeds to sympathise with that given their own lack of preparation time.
The Swiss attacker forced a diving save out of visiting goalkeeper Senne Lammens with a spectacular overhead kick, and visiting heads were in hands when Benjamin Sesko, who is finding it hard to make an impression, turned Zirkzee's cut-back wide from close range.
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 Leeds' 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, squandered.
With the Africa Cup of Nations reaching its latter stages, Amorim could be understood for hoping the involved countries make a pretty quick exit.
Existing injuries to captain Bruno Fernandes and England international Mason Mount only heightened the impact the unavailability of other attackers is having on the team's options.
It's not that the missing pair are the answer to all of United's problems. After all, they were part of the side that experienced disappointing results earlier in the campaign.
But without them, Amorim has few alternatives in attack.
He clearly does not trust youngster Shea Lacey or the much more experienced Zirkzee, even though the Netherlands forward provided the assist for Cunha's equaliser almost immediately after his arrival as a substitute.
That leaves Cunha, who has now scored a small tally in recent outings, and others playing out of their preferred positions, alongside Benjamin Sesko.
On this evidence, the expensive frontman looks similar to previous struggling signings, lacking in confidence 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 biggest rivals to Elland Road was a bit drab affair.
True, there were moments of expected fervor, but the intimidating edge was not as pronounced as in other fixtures.
Leeds' fans were more preoccupied about their side's inability to get worthwhile possession in advanced areas for any length of time.
The Calvert-Lewin header that clipped the post was an isolated moment of threat in a tight first half.
It still felt as though Leeds were finding it tough when a defensive error opened the door for the opener.
Ever so briefly, Leeds' ecstatic fans thought they were about to secure a rare win against their old foes.
However, there is a much bigger picture for the manager and Leeds to deal with.
When they endured a poor run of form earlier in the season, many speculated about the manager's future.
In contrast, he is now masterminding clear progress.
The task is not completed yet but gradually, Leeds are getting closer to achieving 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 FA Cup journey with a home tie.
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