Erik ten Hag’s tricky second album at Manchester United started with a victory but few will understand how. The hosts were dominated by a Wolves team that changed manager days before the start of the season and United were lucky not to concede a penalty in added time but still ended with the points.

Wolves missed a collection of chances to at least get a point out of the match as Raphaël Varane’s header settled the result. Many will feel Wolves should have had a final chance to level matters in the dying seconds of the match when André Onana clattered into Sasa Kalajdzic, only for the referee, Simon Hooper, and his VAR colleagues to decide the challenge required no punishment, despite the goalkeeper getting nowhere near the ball.

Related: Wolves’ Gary O’Neil perplexed by non-award of penalty at Manchester United

The new season was met with protests outside before kick-off as fans expressed their upset with the Glazer ownership of the club and they were joined by a separate manifestation regarding Mason Greenwood, while United debate whether to bring him back into the fold. They have delayed an announcement of his potential return after an internal investigation into the forward. Inside the ground there were banners and loud chants of “We want the Glazers out,” as frustration that the potential sale of United drags on.

Onana’s debut was far more memorable than Mason Mount’s, with the former Chelsea midfielder, like his new teammates, unable to affect proceedings in the final third. He was selected alongside the captain, Bruno Fernandes, to play ahead of Casemiro but the newly configured midfield spent most of the evening watching Matheus Cunha cut through the heart of them.

The Brazilian showed why Julen Lopetegui was so keen for Wolves to spend heavily on him but the departed Spaniard did not get as much out of him in five months as his replacement, Gary O’Neil, did in 77 minutes at Old Trafford. Unfortunately for Wolves, they were unable to find a vital goal, showing evidence of why they scored only 31 times last season. O’Neil has got the players well drilled already, bringing a new identity to the team, something that got the fans chanting his name from early on.

It is harsh to criticise Cunha considering how much effort and dynamism he brought to Wolves but he will be frustrated he was unable to beat Onana. He was not the only culprit for the visitors, with Pedro Neto and substitute Fábio Silva having good chances without success. The visitors had 23 shots, the most from an away team in the league at Old Trafford since 2015, but only six on target, although the performance will give them hope that things are not as bad as it seemed when Lopetegui walked away last week.

United were flat throughout, relying on two defenders to combine for the winner as their attackers struggled to create much in the final third. After 76 minutes of misplaced passes and quarter chances, Aaron Wan-Bissaka latched on to a sublime Bruno Fernandes pass, before lifting the ball to Varane to head home from close range.

Many would have thought the goal would have lifted United and knocked Wolves’ confidence but instead the hosts retreated further into their shell as Wolves continued their dominant performance, forcing Onana into a number of saves and defenders into last-ditch blocks.

Last campaign United lost their two opening games and they will be relieved supporters left Old Trafford with vague smiles on their faces, although many questions remain about how the side build on Ten Hag’s first season improvements. New signing Rasmus Højlund was unavailable because of a back problem, not that the presence of a striker is much use when a side is unable to create chances. They had three shots on target as José Sá was allowed a quiet night.

Wolves cut through United with ease on a regular basis, Casemiro unable to hold back Cunha who showed incredible stamina and dribbling skills to take the ball up the pitch. Lisandro Martínez was taken off at the break after picking up a yellow card for a late challenge on Neto, an example of United’s struggles against a club in flux.

United will not be too bothered how the win came but they should have left with a point at best. Onana had a solid game in his first United appearance but should have ended it by facing a penalty when he jumped to catch a cross and caught Kalajdzic in the face without the ball in sight. Hooper did not immediately award the spot-kick but there was a hush inside the stadium as VAR reviewed it, only to determine there was not sufficient evidence to overturn the original decision.

Wolves think otherwise, although United will be happy to let their complaints fall on deaf ears because their season is up and running, even if it was completely undeserved.