The Juventus forward believed he had snatched all three points in Belgrade during an enthralling World Cup qualifier when his goalbound effort was hooked off the line by Stefan Mitrovic.
Replays suggested the ball had crossed the line, despite Mitrovic’s valiant effort to hack the ball off the line, with no Video Assistant Referee or technology in place to provide clarity.
The ending was befitting of a game packed with quality, which saw Fulham striker Aleksandar Mitrovic became Serbia’s all-time top goalscorer as he netted his 39thgoal in 63 appearances.
The hosts had to fight back from two goals down to grab what could be a vital point in the race to reach Qatar.
Stefan Mitrovic cleared Ronaldo’s effort off the line in Belgrade
Replays suggested the Juventus forward had in fact scored for Portugal
The 36-year-old had no VAR or goal line technology to prove his claims
Mitrovic pulled one back in the 46th minute and Filip Kostic levelled after a brace from Diogo Jota had given Portugal a 2-0 lead in the first half.
Liverpool forward Jota fired the European champions ahead with an 11th-minute header from a superb Bernardo Silva assist and added another in the 36th as he glanced a Cedric Soares cross from the right.
But Serbia roared back at their Rajko Mitic stadium and halftime substitute Nemanja Radonjic, who engineered both their goals, gave his markers a roasting after the break and also drew a fine save from Portugal goalkeeper Anthony Lopes.
Serbia defender Nikola Milenkovic was sent off in stoppage time, having been shown a straight red card for a reckless challenge on an opponent.