The Indomitable Lions, with regular goalkeeper Andre Onana reportedly on his way home after a falling out with coach Rigobert Song, scored first through Jean-Charles Castelletto only for Serbia to seize control through goals from Strahinja Pavlovic, Sergej Milinkovic-Savic and Aleksandar Mitrovic.
It seemed Dragan Stojkovic's men were cruising but they were stung by two goals in three second-half minutes, substitute Vincent Aboubakar's clever finish reducing the arrears before Eric Choupo-Moting brought Cameroon level.
Serbia bossed the bulk of the first half but had to wait until just before half-time to make their superiority count in the Group G clash at Al Janoub Stadium on Monday.
Mitrovic fired a left-footed strike against the post in the sixth minute following a neat one-two with Dusan Tadic and, six minutes later, came close again by shooting wide from close range after the ball bobbled around the Cameroon box.
Serbia were made to pay for his profligacy when Cameroon took the lead approaching the half-hour mark.
Pierre Kunde whipped in a corner from the left that was flicked on by Nicolas Nkoulou and Castelletto tapped in at the far post.
Cameroon could have doubled their advantage after 43 minutes but Kunde fired straight at goalkeeper Vanja Milinkovic-Savic when clean through before slicing the rebound horribly wide.
It was to prove a critical moment as Serbia turned the game around before the break.
First, Pavlovic headed in Tadic’s floated free-kick before Sergej Milinkovic-Savic drove home from the edge of the box, although Onana's deputy Devis Epassy should have done better.
Mitrovic got the goal his all-round display deserved eight minutes into the second half.
Lovely interplay from Filip Kostic and Sergej Milinkovic-Savic enabled Andrija Zivkovic to find space on the right side of the area and his cut-back was perfect for Mitrovic to tap into an empty net.
Cameroon appeared to be beaten but the 55th-minute introduction of Aboubakar turned the game on its head.
The Al Nassr striker made it 3-2 after 64 minutes, running on to Castelletto's through ball before producing an impudent scoop over Serbia goalkeeper Vanja Milinkovic-Savic - the goal given after a VAR check.
He then turned provider two minutes later, escaping down the right before crossing for Choupo-Moting to fire in.
Mitrovic could have clinched it but shot straight at Epassy.
What does it mean? Cameroon teetering on the brink of elimination
The draw ended Cameroon's run of eight successive defeats at the World Cup. Qualification for the knockout phase is still unlikely, however. Song's men will have to beat Brazil on matchday three and hope other results go their way.
Serbia also need to win their final match against Switzerland on Friday to have any chance of staying in the tournament.
Mitrovic the hero and villain
Fulham striker Mitrovic scored and was a constant menace to the Cameroon defence, but wasted numerous chances to put Serbia out of sight.
He ought to have scored twice in the first half and, with a chaotic game delicately poised at 3-3, should have done better late on than fire straight at Epassy.
Aboubakar provides Cameroon's spark
Aboubakar has surprisingly not started either of Cameroon’s games in Qatar despite finishing as the top scorer at the 2021 African Cup of Nations, played earlier this year.
The former Porto man was brilliant following his introduction. Named man of the match despite coming on in the 55th minute, he enjoyed a team-high five touches in the opposition box and three shots, two of which were on target.
Key Opta facts
- Cameroon claimed their first World Cup point since beating Saudi Arabia 1-0 back in 2002.
- It was Serbia's first World Cup draw and the first time they have scored as many as three goals in the competition.
- Cameroon also scored three goals for the first time in a World Cup match, while it was the first time in 16 games they have found the back of the net more than once in the competition - last doing so in a 2-2 draw with Sweden in 1994.
- There were 148 seconds between Serbia equalising and taking the lead and they became the first team to score twice in first-half added time in a World Cup match.