Brazilian striker Ronaldo, playing only his second game since a knee injury last year, scored an injury-time equaliser to give his new club Corinthians a 1-1 draw with arch-rivals Palmeiras on Sunday.
Ronaldo, who came on as a second-half substitute, was booked for climbing the fencing around the pitch to celebrate with the supporters after heading home at the far post from a corner in the second minute of injury time.
Part of the fencing gave way but nobody appeared to be hurt. Police rushed in to restore order and allow the game to continue.
"I'm very sorry for the incident, but I couldn't contain my emotions," Ronaldo said in a touchline interview.
Ronaldo, who defied predictions that he would have to end his career after the injury 13 months ago, later told a news conference: "It was a big fright, it was a rather irresponsible attitude because the fence wasn't so strong after all. But you don't think at the time, you just want to celebrate with the fans.
"It's always emotional to bounce back.
"I can't explain what I felt but I certainly thought about .... all the difficult moments I've had in this recovery."
Ronaldo vowed there was more to come.
"This is just the beginning. There's still some way to go .... I need to lose a bit of weight and gain some speed and mobility."
The 2002 World Cup winner ruptured a tendon in his left knee in a Serie A game playing for AC Milan against Livorno in February last year.
It was the third such injury of his career and came when he was already suffering from a loss of form and fitness problems.
"They said he would never play again and there he is scoring a decisive goal in an important game," Corinthians coach Mano Menezes said.
Ronaldo left Milan and joined Corinthians in December.
He made his first appearance last Wednesday, also as a second-half substitute, and suffered a black eye after being hit by a microphone as reporters invaded the pitch after the final whistle.
A capacity-crowd of 45,000 packed the Prudentao stadium in Presidente Prudente, 580 km from Sao Paulo, for the Paulista championship match on Sunday.
The three-times World Player of the Year came on in the 64th minute with Palmeiras 1-0 ahead, Diego Souza having scored in the 48th minute, and dominating the game.
Ronaldo struck the crossbar with a shot from outside the area before scoring his first goal since January last year, when he was on target for AC Milan against Napoli.
Palmeiras coach Vanderlei Luxemburgo was unimpressed and criticised the referee.
"I think he wanted Ronaldo to score a goal," said the former Brazil and Real Madrid coach.
"He kept awarding free kicks near our penalty area. I think the referee was affected psychologically (by Ronaldo's presence).