Japan surprised Argentina 1-0 in Saitama on Friday, landing a blow to caretaker coach Sergio Batista's designs on the full-time job.
Shimizu S-Pulse striker Shinji Okazaki grabbed the only goal in the 19th minute at the Saitama Stadium 2002, handing new Japan coach Alberto Zaccheroni a debut victory.
Argentina fielded a full-strength team for the international friendly, including newly crowned European Golden Boot winner Lionel Messi, but the South American powerhouse were unable to take any of their chances.
Messi missed two early opportunities before Okazaki stunned the beaten 2010 World Cup quarter-finalists.
The 24-year-old J-League player reacted quickest to a parry from Argentina goalkeeper Sergio Romero, latching onto the ball and slotting it home for an unlikely opener.
Messi and Manchester City's Carlos Tevez both missed chances to equalise, while Japan also went close to doubling the lead through Keisuke Honda and Ryoichi Maeda.
"I feel very happy. My debut match turned out to be such an important event," Zaccheroni said."I told my players before the match that if you work hard it will produce a result."
In other friendlies, China defeated Syria 2-1 at the Tianhe Stadium in Guangzhou.
Zhao Peng opened the scoring for China in the 39th minute, following up a rebound after a Du We header was saved by Mosab Balhous in the Syria goal.
Linpeng Zhang extended China's lead from the penalty spot six minutes into the second half after Aattef Jeneiat handled in the box, for which the defender was sent off.
Abdelrazaq Al-Hussain followed up a Ziad Chabo free kick to pull one back for 10-man Syria on the hour mark, but China held out for the win.
Indonesia were handed a 7-1 thrashing by 2010 World Cup semi-finalists Uruguay in a friendly in Jakarta on Friday.
Boas Salossa put Indonesia 1-0 up in the 17th minute at the Gelora Bung Karno Stadium, but Uruguay were ahead by the break thanks to goals from Napoli's Edinson Cavani and Luis Suarez of Ajax Amsterdam.
Suarez made it 3-1 nine minutes into the second half before Sebastian Eguren got in on the act four minutes later.
Suarez claimed his hat-trick from the penalty spot in the 69th minute, while Cavani added two late strikes for his own hat-trick to leave the star men fighting over the match ball.
An Anatoliy Tymoschuk equaliser saw Ukraine claim a 2-2 draw with Canada in Kiev.
The 88th-ranked Canada are 62 places below Ukraine on the FIFA world rankings but you would not have known going by the first-half.
Goals from Norwich City striker Simeon Jackson and Atiba Hutchinson, in his 50th international, gave Canada a 2-0 lead after 45 minutes.
Artem Milevskiy pulled a goal back for the hosts after 59 minutes before Tymoschuk's intervention ensured the spoils would be shared.
Luis Ramirez and Hernan Rengifo struck in the first six minutes as Peru defeated Costa Rica 2-0 while Bahrain defeated Kuwait 3-1.
India were also 3-1 winners, defeating Vietnam while Oman edged Gabon 1-0.