It turned out that painful defeat against Malaysia was really a precaution.

South Korea defended their men's football title at the 18th Asian Games on Saturday after beating Japan 2-1 in extra time. It was their fifth gold medal in Asiad men's football, the most of any Asian nation.

South Korea's gold run in Indonesia was never perfect. At Incheon 2014, South Korea became champions without suffering a defeat or conceding a goal, but this time, they took a bumpier road.

Kim Hak-bum's side were thought to be the best under-23 team that South Korea has ever sent to the Asian Games. Along with Tottenham Hotspur star Son Heung-min, three players -- Jo Hyeon-woo, Hwang Hee-chan and Lee Seung-woo -- had been to the 2018 FIFA World Cup. 

They had a dream start at Jakarta-Palembang 2018 by crushing Bahrain 6-0. But everything changed in the next match.

In probably the biggest upset at the Asian Games, South Korea suffered an unexpected 2-1 loss to Malaysia, which cost them a top finish in their group.

South Korea later beat Kyrgyzstan 1-0 in their final group game, but Malaysia had already taken the top spot. Finishing the group as runners-up gave South Korea a difficult path to the final

by facing tough opponents like Iran and Uzbekistan.

After the Malaysia defeat, Kim and the players vowed that they would not give the same performance again. They added that the defeat would serve as a wake-up call, causing the players to stay alert throughout the competition.

South Korea showed that they were not just throwing out words.

With a superb performance from Hwang Ui-jo, they were able to carry on.

Hwang, who already had a hat trick against Bahrain and a goal against Malaysia, helped in South Korea's 2-0 win over Iran in the round of 16 by netting the team's second goal. But South Korea saw their No. 1 goalkeeper Jo Hyeon-woo picking up a knee injury.

Without Jo, South Korea had to take on Uzbekistan, the winners of the 2018 AFC U-23 Championship in the quarterfinals. But Hwang delivered a memorable one-man show by scoring a hat trick and earning a penalty to lead South Korea's 4-3 win in extra time.

The narrow win over Uzbekistan was another moment that South Korea had to regroup and set themselves straight. Kim later told reporters that he scolded the players that they should not perform again like they did against Uzbekistan.

In the semifinals, South Korea had to face Vietnam, the team coached by South Korean Park Hang-seo. But South Korea collected a relatively easy 3-1 win, thanks to two goals by Lee Seung-woo.

With just one match left to accomplish their mission, South Korea had to face archrivals Japan, and it was as tough as usual.

Both teams finished the regulation 90 minutes scoreless and were forced to extra time. Lee Seung-woo swayed the match in South Korea's favor with his left-footed strike in the 93rd, and Hwang

Hee-chan doubled the lead with a header in the 101st.

Japan kept up the intensity of the match by cutting the deficit to one with Ayase Ueda's goal in the 115th. However, South Korea

were able to hold on to the lead to seal the victory -- and the gold. 

Next for the under-23 players and wild card members -- Son Heung-min, Hwang Ui-jo and Jo Hyeon-woo -- will be going back to their respective clubs and to build up their careers without worrying about military service.

South Korean male athletes who earn an Asiad gold or any Olympic medal are exempted from compulsory military service, which is about two years long. With that out of the way, the members of

this gold-medal winning team have nothing to do but work hard.

Eight players will have to carry their winning momentum into the senior side. While four players -- Son, Jo, Lee Seung-woo and Hwang Hee-chan -- have already showed their skills at the 2018 FIFA

World Cup, players like Hwang Ui-jo, Kim Min-jae, Hwang In-beom and Kim Moon-hwan will have to prove they are worth senior team selection.

Hwang Ui-jo wrapped up the men's football competition as the top scorer with nine goals and will hope he can keep up his goal-poaching on Paulo Bento's team. Kim was a core center back for

South Korea before he got injured and will have to show his talent again.

Hwang In-beom and Kim In-beom earned their first senior team selection, and for them, the real challenges may have just begun. (Yonhap)