Colombia coach Jose Pekerman blamed his team’s World Cup defeat to Japan on fatigue after they played almost the entire match with a man less.
Carlos Sanchez was sent off after just three minutes for handling Shinji Kagawa’s shot, with the Japan playmaker slotting home the resulting penalty.
Colombia recovered to draw level through Juan Quintero’s free-kick before half-time, but Yuya Osako’s 73rd-minute header secured all three points for Japan at a time when they were the superior team.
Pekerman’s team had been the favourites in Saransk, but Japan increasingly impressed as the game unfolded.
“Normally you prepare to play 11 against 11, it’s not easy to lose such a crucial player in the first three minutes,” he told reporters, according to FIFA’s official website. “We managed to survive in the first half. We even got to a draw, even with one player less.
“Despite that, in the second half, Japan managed to adapt to the situation. They managed to score, and played better, and by taking advantage of the opportunities that emerged.
“Japan had that extra man in defence.
“We wanted to attack with players such as (Carlos) Bacca and James (Rodriguez). Especially because Quintero felt the effects of the first half, and started the second half rather tired.
“Even though we played with 10 we proved we could draw the match, which is what we actually did at one stage.
“The pain we feel is because after a huge effort, we lost because we were worn down, we were tired, we lost this opportunity. Even if I tried subbing on fresh players, it was very hard for us to recover possession.”
Colombia now face Poland before completing their Group H campaign against Senegal, and Pekerman said: “We’ll see if we can make up for this defeat in the next two matches.”
Japan boss Akira Nishino admitted his team’s game plan became about exploiting the fact Colombia had been reduced to 10 men.
Despite the victory proving Japan’s first at a World Cup in Europe, in six attempts, he also warned they remain far from certain of progressing to the competition’s knockout stages.
“I said at half-time that if we can keep the ball moving, we can deprive the Colombia players of their stamina,” said the 63-year-old, according to FIFA.
“Our players were aggressive from the start and I think that worked very well for us.
“This is just one win and three points, so we will save our celebration.”
Man of the match Osako added: “To score a goal in the World Cup has been a dream for me since I was little, so I am extremely happy.”