Cameroon took their time but Saudi Arabia finally bowed to the inevitable when Samuel Eto'o scored to spare the Africans' blushes.
The Indomitable Lions were always on the front foot and hoping for a repeat of Germany's 8-0 win over Saudi in their opening game.
But despite having two goals ruled offside, Cameroon created few genuine chances and their finishing was disappointing.
Saudi Arabia, meanwhile, who became the first team to go out of the 2002 World Cup, will count themselves unlucky not to have scored.
The victory leaves Cameroon second in Group E on goal difference behind Germany.
And it leaves the door wide open for Ireland to qualify for the second round if they beat Saudi by 2-0 or more on 11 June.
Cameroon began the match in ominous fashion, with claims for a penalty inside 20 seconds.
Daniel Ngom Kome, the only change to the Indomitable Lions' line-up which drew 1-1 with the Republic on Saturday, was felled in the area by Mohammed Al Jahani.
But Norwegian referee Terje Hauge waved away the appeals.
The Saudis took heart from their early let off and nearly took the lead when Obeid al Dossary headed over the bar from close range from Ibrahim Al Shahrani's cross.
But the pattern of the game swiftly took shape as Cameroon launched repeated attacks, interspersed with the occasional Saudi raid.
Cameroon's Patrick Mboma did find the net in the 11th minute after latching onto a through-ball in the box but was ruled offside.
Al Dossary (left) went close for Saudi Arabia
The Africans continued to press, but against the run of play, Al Dossary found himself one-on-one with Cameroon's goalkeeper, only to be flagged belatedly and somewhat harshly for offside.
Cameroon were cruising but not quite in top gear and despite a couple of speculative long-range free kicks from Pierre Wome they created few openings.
But Saudi's fortunes took a turn for the worse on the half hour when dangerman Al Dossary fell awkwardly and was carried off to be replaced by Al Hassan Al Yami.
I'm a Lion and I really want to get to the second round
Cameroon coach Winnie Schafer
Saudi resistance remained intact but Cameroon's attacks gathered pace inside the last ten minutes of the half.
But again Saudi nearly took a shock lead when Al Yami threaded a ball through for Nawaf al-Temyat, who toe-poked it just wide.
On the stroke of half-time, Cameroon's Lauren found the net again but was denied as one of his colleagues was rule offside.
Cameroon continued to pour forward after the break and went close on several occasions, notably a long-range strike from Lauren.
Substitute Salomon Olembe, on for Kome, was a catalyst for many of the attacks and his run gave Eto'o Cameroon's best chance, only to blaze it high and wide.
But Saudi were unperturbed and had a good chance of their own when Al Temyat played through Al Yami, who lifted his shot over the bar.
Al Temyat was again the instigator when Saudi saw their claims for a penalty rewarded with a yellow card for diving for Al Yami.
But Saudi's forays were merely putting off the inevitable and Cameroon finally struck on 64 minutes when Eto'o fired home after racing onto Geremi's through-ball.
Cameroon: Alioum, Wome (Njanka 84), Tchato, Song, Kalla, Lauren, Foe, Kome (Olembe 45), Geremi, Eto'o, Mboma (N'Diefi 74).
Subs Not Used: Alnoudji, Djemba-Djemba, Epalle, Job, Kameni, Mettomo, Ndo, Songo'o, Suffo.
Goal: Eto'o 65.
Saudi Arabia: Al Daeyea, Al Jahani, Tukar,
Zubromawi (Abdallah Al Dossari 71), Al Shehri, Sulimani,
Al Khathran (Noor 86), Abdallah Al Shahrani,
Ibrahim Al Shahrani, Al Temyat, Obeid Al Dossari (Al Yami 35).
Subs Not Used: Ahmed Al Dossari, Al Ghamdi, Al Jaber, Al Owairan, Al Shlhoub, Al Thagafi, Babkr, Harthi, Zaid.
Booked: Al Yami.
Referee: T Hauge (Norway).
MATCH STATS |
| Cameroon | Saudi A |
Corners (1st half) | 4 | 0 |
Corners (2nd half) | 4 | 1 |
Fouls committed | 13 | 9 |
Caught offside | 6 | 3 |
Shots on target | 5 | 4 |
Shots off target | 9 | 11 |
Hit woodwork (back into play) | 0 | 0 |
Yellow cards | 1 | 1 |
Red cards | 0 | 0 |
STOPPAGE TIME | |
First half - 2 mins | Second half - 4 mins |