Ronaldo completed 45 minutes for United after missing the rest of pre-season
Ronaldo's United future has been the subject of intense debate this summer.
The 37-year-old is keen to move away from the club to pursue his desire to compete in the Champions League.
And he was allowed to miss United's pre-season tour of Thailand and Australia for personal reasons.
Ronaldo made a point of applauding fans on both sides of the stadium as he led the outfield players out for their warm-up before kick-off, with the supporters reciprocating to show there is no lingering ill-feeling despite the summer speculation.
The Portuguese had one clear chance during his 45-minute appearance against the La Liga side but drove over after running on to Donny van de Beek's lay-off.
Although Ronaldo seems certain to still be a United player when his club open their Premier League campaign against Brighton on 7 August, it is doubtful whether this cameo will get him a starting slot against Graham Potter's men.
New signings Christian Eriksen and Lisandro Martinez both featured for an hour in a game set up by new manager Erik ten Hag for the players who were not involved extensively in Saturday's 1-0 defeat by Atletico Madrid in Oslo.
In Ten Hag's first game in charge at Old Trafford, Ronaldo was upstaged by 18-year-old Argentine Alejandro Garnacho.
In a goalless first-half, Garnacho carried the greatest threat, cutting in from the left-wing to cause the visitors problems.
Garnacho is one of a number of young players Ten Hag is still to decide whether to keep or allow to leave on loan.
Ivorian Amad Diallo is another after spending last season at Rangers.
And it was the 20-year-old who put the hosts in front at the start of the second half when he turned home the rebound after Alex Telles' shot had been saved.
United's lead lasted just nine minutes before Alvaro Garcia equalised in similar fashion after Tom Heaton had saved Isaac Palazon Camacho's initial effort.
Liverpool fielded a much-changed line-up a day after beating Manchester City in the Community Shield and went down to a 3-0 defeat by Strasbourg.
Leicester City playmaker James Maddison and defender Wesley Fofana have been linked with moves away from the Foxes but both started the 1-0 win against Sevilla.
Maddison found Kiernan Dewsbury-Hall, who then scored the winner for manager Brendan Rodgers' side.
Fulham went behind to a Dani Parejo goal for Villarreal but earned a 1-1 draw following a late Aleksandar Mitrovic strike.
Wolves, who had drawn with Sporting Lisbon on Saturday, also came back from a goal down to draw 1-1 with Farense thanks to a Hwang Hee-chan penalty.
Leeds United striker Rodrigo scored a hat-trick as he helped his side beat Cagliari 6-2, with fellow forward Patrick Bamford netting two goals and Robin Koch the other for the Elland Road club.
-- Courtesy of BBC Sport