Chelsea were the better side. But Ronaldo’s goal salvaged a point for the Red Devils at the Old Trafford.
Ronaldo, who has now scored United’s last five goals, found the net just two minutes after Chelsea had taken a deserved 60th-minute lead through Marcos Alonso.
Ronaldo came into the game having scored a hat trick against Norwich and another goal against Arsenal in his previous two games.
With 17 goals, Ronaldo is tied with Son Heung-min in second place in the Premier League scoring chart behind Mohamed Salah.
“Not only the goal Cristiano scored but his whole performance, his attitude at age of 37, this is not normal to do that, “interim United manager Ralf Rangnick said. “If he plays like he did today, he can still be a big help to this team.”
Reece James later curled a shot against the post for Chelsea, which dominated the first half but found United goalkeeper David de Gea in fine form.
With only three games left to play in the league, United stayed in sixth place — five points behind fourth-place Arsenal and having played two matches more than its rival for Champions League qualification.
Tottenham is between the two teams, in the fifth spot, with three more points than United and two games in hand.
Chelsea consolidated third place and is six points above Arsenal.
It was another night of mediocrity from Ralf Rangnick’s United side as their troubled season, which began with such high expectations, peters out. The result leaves Chelsea in third place on 66 points while United is at the sixth spot with 55, five points behind fourth-placed Arsenal, having played two games more.
The only moment of class to bring some cheer to supporters who had again vented their frustrations against the club’s American owners, the Glazer family, came from Ronaldo with a superb piece of control and finishing.
Despite controlling much of the game, Chelsea failed to make the most of a host of chances in a contest between two teams whose tumultuous seasons are drifting toward their conclusion.
“One team deserved to win and that was us. We didn’t take it. It was a very, very good performance but we were not decisive enough. We lacked a bit of determination in the box to win the game,” Chelsea manager Thomas Tuchel said.
“It sometimes happens. It’s on us to learn from it. You need to be clinical to get the reward. We have to live with a point, but it’s not a fair result.
“We worked so hard to get the lead and suddenly the opponent gets one free shot and scores.”