Moises Caicedo put a stop to Manchester United's nascent revival under Ruud van Nistelrooy with a stunning volley. The Ecuadorian's second-half strike helped Chelsea leave Old Trafford with a point.
Van Nistelrooy, who took over as caretaker manager after Erik ten Hag was sacked last week, inspired United to a 5-2 Carabao Cup win over Leicester City, his first game in charge.
In the match against Chelsea, Bruno Fernandes put the "Red Devils" ahead when he successfully converted a penalty in the 70th minute. However, the home team's hopes of winning were extinguished just 4 minutes later by Caicedo.
Van Nistelrooy will remain in charge for the Europa League games against PAOK Thessaloniki and the Premier League against Leicester. Ruben Amorim will then arrive on November 11 to become United's sixth permanent manager since Sir Alex Ferguson retired in 2013.
The former Sporting boss will need to inspire a turnaround quickly to get United back on track this season.
Van Nistelrooy's natural attacking instincts have made the difference for United in the last two games, but the scars from Ten Hag's cautious approach remain deep in the players' minds.
United's weakness is underlined by the fact that they have led for just 90 minutes in the Premier League this season, and 55 of those minutes have come against struggling Southampton.
Incredibly, for a club with the resources of Man United, only Southampton and Crystal Palace have scored fewer goals than them in the league this season.
The Red Devils' five-goal performance in the midweek win over Leicester was an example of them playing more freely under Van Nistelrooy. And they were also very skilful against Chelsea. But while United were often caught out when attacking under Ten Hag, they also struggled and were cautious when playing out from the back. And Van Nistelrooy was quick to put an end to any repeat of that against Chelsea.
The former Manchester United striker clearly wanted his players to move forward whenever they had the ball, but a key mistake made under Ten Hag was that players often took the safest option of passing the ball backwards.
When defender Matthijs de Ligt did so in the first half, passing back to goalkeeper Andre Onana instead of forward to Alejandro Garnacho, Van Nistelrooy berated the Dutchman on the touchline.
There were plenty of other times Van Nistelrooy pointed forward, but when a team is struggling like United, players tend to take the easy way out to reduce the risk of making mistakes. It is a problem that continues to plague the Old Trafford side at the moment.
"It's been an emotional journey. It's been almost a full week from Monday to today with a lot happening. My job is to steady the ship and get the team back on track.
"I think the players responded well on Wednesday and today. That's the foundation to build on for the next two games," Van Nistelrooy said after the draw with Chelsea.
