It's "too early" to call Manchester United Premier League and Champions League contenders, according to Dimitar Berbatov, who says the Red Devils need to become consistent again.
United are beginning to hit their stride after a slow start to the 2020-21 season.
Ole Gunnar Solskjaer's are unbeaten in four matches since their return to action after the international break, with defensive leaks plugged and a cutting edge in the final third rediscovered.
The Red Devils beat Newcastle 4-1 away and produced a solid performance in a 0-0 draw at home to Chelsea in the Premier League, but have so far saved their best displays for the European stage.
A 2-1 win over Paris Saint-Germain at Parc des Princes was followed up by a hugely impressive 5-0 victory against RB Leipzig at Old Trafford on Wednesday, with Marcus Rashford grabbing the first hat-trick of his career and Mason Greenwood and Anthony Martial also getting on the scoresheet.
Solskjaer has talked up United's chances of making it all the way to the final, while admitting that the Premier League title race is open amid the continued absence of supporters, but Berbatov says there is still work to be done before his old club can be considered as genuine challengers for major honours.
"This result at home will do wonders for United's confidence, as their home record hasn't been fantastic. Not only have they won at home, they've beaten Leipzig 5-0! That is an incredible result," the ex-Red Devils striker told Betfair.
"Hopefully, this win will change their fortunes going forward.
"Ole deserves credit for performances like this, it can't be a situation where good results are the players, the bad results are the manager, that does not work.
"I wouldn't jump to the conclusion that United all of a sudden can win the Premier League or the Champions League, it is too early and they need to become that word again - consistent.
"They have lacked this over the last while, if they find that then we can wonder about titles, but they need to win games regularly."
Berbatov added on how effective United's forwards were in the final third against Leipzig: "Marcus Rashford was amazing. To score a hat-trick coming on as a sub speaks volumes. By now, he's well established as a superstar, but the impact he had when he came on was just outstanding.
"Sometimes when you come on as a sub, you don't feel right, or you're annoyed not to start, and you don't play well. For Marcus, he knows he is integral to the team, and Ole would've explained to him that he was going to rest him. This allows him to relax about his position and focus on playing.
"All the attackers had the ball in the net, though [Edinson] Cavani had his disallowed, but it's fantastic to see all your attackers in a rhythm like this. There was controversy that maybe [Mason] Greenwood was offside, but I don't think he was - maybe a toenail, but to me he was onside.
"I was happy to see him bag his goal, he is a brilliant talent."
The Red Devils will be back in Premier League action at home to Arsenal on Sunday, three days before they take in a trip to Turkey to take on Istanbul Basaksehir in the Champions League.