Tottenham Hotspur forward Son Heung-min's first-half header earned South Korea victory over Cameroon in a friendly in Seoul on Tuesday.
The 30-year-old nodded home a rebound in the 35th minute after Kim Jin-Su's strike was parried by Indomitable Lions keeper Andre Onana.
The Central African nation, who fell 2-0 to Uzbekistan on Friday, have now suffered two defeats in their final warm-ups prior to naming their World Cup squad.
Coach Rigobert Song named a strong side against the Asians in the South Korean capital, but Nicolas Moumi Ngamaleu's ambitious long-range effort was just wide midway through the first half.
Cameroon, who fielded Brentford's Bryan Mbeumo throughout, had missed chances through Olivier Ntcham, Martin Hongla, and Pierre Kunde, while Léandre Tawamba saw his stoppage-time effort saved.
The five-time African champions, who begin their World Cup campaign against Switzerland and are also grouped with Brazil and Serbia in Group G at the finals, will host Jamaica in a friendly in Yaounde on 9 November before leaving for Qatar, according to Song.
In another early kick-off, African champions Senegal drew 1-1 with fellow World Cup-bound Iran in Austria.
Senegal took the lead after 55 minutes when defender Morteza Pouraliganji struck into his own net from an acute angle.
The Teranga Lions, who beat Bolivia 2-0 on Saturday, held onto their lead for only nine minutes before Sardar Azmoun equalised, the Iran forward heading home from a cross by left back Ehsan Hajsafi.
Aliou Cisse's men will play Netherlands in their opening fixture in Qatar, followed by clashes with the hosts and Ecuador in Group A.
Later on Tuesday, Morocco were held to a goalless draw by Paraguay while Ghana beat Nicaragua 1-0, thanks to a goal from teenager Abdul Fatawu Issahaku, as both sides continue their World Cup preparations.
Elsewhere, Tunisia - Africa's fifth representative at the finals - were beaten 5-1 by world champions Brazil in a game marred by racism against South American forward Richarlison.
In other results involving sides not heading to Qatar, Egypt defeated Liberia 3-0, Algeria beat Nigeria 2-1 and the next Africa Cup of Nations hosts, Ivory Coast were too good for Guinea, winning 3-1.
Elsewhere, torrential rain and stormy weather conditions forced the abandonment of Mali and Zambia's second friendly game in four days in Bamako on Monday night.
The game was stopped after 15 minutes following a heavy downpour which flooded the pitch.
Some reports suggested that Zambia did not return to the pitch before it was eventually called off by the match officials, but Fashion Sakala rejected such claims.
The Rangers forward insisted the Chipolopolo players wanted to impress after Friday's 1-0 loss in the Malian capital.
"We wanted to play and avenge our defeat on Friday but it's unfortunate that the game was cancelled," he said.
"We started well and were highly-motivated to win, everyone wanted to beat Mali but the weather ruined things."