Ronaldo was given a hero's send-off by Brazil fans despite missing three chances in the 15 minutes for which he was on the pitch in a lacklustre 1-0 win over Romania in a friendly in Sao Paulo.
Ronaldo, 34, retired in February saying he struggled to keep his weight in check for the rigours of top-flight football due to a thyroid problem.
He looked rather chubby against the Romanians yet showed great positional sense to get himself in position to score - but his famed finishing skills deserted him on the day.
"People, you are too much. Please forgive me - I had goal chances and I didn't manage to score in my last match, my last 15 minutes," said Ronaldo, wrapped in a Brazilian flag, after a lap of honour of the Pacaembu where he played for his last club Corinthians.
"I can only thank you for all your support, all the love the Brazilian people have given me all these years," he told the crowd from the centre circle at half-time.
The striker, who played for both Milan clubs and Spanish rivals Barcelona and Real Madrid in a brilliant career, was inside the six-yard box ready to tap in Maicon's low cross from the right but goalkeeper Ciprian Tatarusanu blocked.
Robinho then set the unmarked Ronaldo up with an easier chance but the holder of a record 15 World Cup goals and two winners' medals sliced the ball way over the top.
Neymar then pulled the ball back from the goalline on the right and Ronaldo shot low, forcing Tatarusanu into a good diving save.
Fred, who started the match before making way with 15 minutes remaining in the first half for the former Brazil striker, scored the winner right in front of goal from Neymar's low left cross in the 22nd minute.
In honour of Ronaldo, the entire Brazil team recreated his famous finger wag celebration after the goal.