Cristiano Ronaldo was taken off at half-time with his 10-man Al-Nassr side 2-0 down - before they fought back to seal a dramatic win over Al-Ettifaq.
Defending Saudi Pro League champions Al-Nassr got off to a dreadful start on Tuesday when goalkeeper Bento was sent off after just 12 minutes and they were two goals behind at the break.
Ronaldo, 41, making his first start since the World Cup, left the pitch in frustration at half-time and was then substituted by manager Ange Postecoglou.
But Postecoglou's decisions proved to be vindicated with Al-Nassr launching a second-half comeback.
Sadio Mane and Abdulelah Al Amri scored inside three minutes to draw Al-Nassr level with 13 minutes to go, before former Liverpool forward Mane got the winner in added time.
The win helped Al-Nassr go top of the table after three straight victories this season.
Former Tottenham and Nottingham Forest boss Postegoclou said Ronaldo, who spread his arms in a questioning gesture towards the bench when he was substituted, was taken off as part of a different tactical approach.
"When I made the substitutions, including taking Ronaldo off, I believed the players coming on could make an impact," Postecoglou said.
"I came here to help the players, so as I said, I'm proud of them because every substitute made a positive contribution.
"I'm here to help the team with what I see, and everyone knows that Ronaldo hasn't played in a long time. He performed exceptionally well in the first half, and we opted for a different approach."
Postecoglou took over at Al-Nassr last month after being sacked by Forest last October following just 39 days in charge.
Five-time Ballon d'Or winner Ronaldo married his partner Georgina Rodriguez earlier this month and has said this is likely to be his last season as a player so he can focus more on his family.
