Experienced referee Felix Zwayer went down injured with a cramp in stoppage time of the USA's win over Australia in Seattle.
The 45-year-old needed assistance from the United States' Florian Balogun and Australia's Aiden O'Neill, who stretched out the official's left leg after he fell to the turf.
The referee required an energy gel to see out the last few minutes, which was rushed over to him by fourth official Katia Garcia.
Zwayer got back to his feet and saw out the rest of the contest, which the US won 2-0, moving them to the brink of the knockout stages.
BBC co-commentator Danny Murphy joked: "He needs the bucket and sponge."
The German referee dished out several yellow cards in a dominating performance by the United States.
Temperatures in Seattle reached 26C, with players needing the hydration breaks for the noon-time game.
An own goal by Australia's Cameron Burgess got proceedings on the right track for the United States, created by a brilliant move from Floarian Balogun.
Alex Freeman headed home a second before half-time, who now only need a point from their final game to go through top of Group D.
The US won their opening game with a thumping 4-1 victory over Paraguay and continued their form against the Socceroos.
Even without starman Christian Pulisic, who missed out with a calf injury, Mauricio Pochettino's side were by far the better side throughout.
Patrick Beach stood no chance with both US goals, having been the hero in Australia's first match.
Should Turkey fail to beat Paraguay, the co-hosts will top the group regardless of their result in the final match.
Australia needs just a point against Paraguay to ensure they qualify for the last 32.
Pochettino spoke positively of his players finding a way past the Socceroos without Pulisic.
He said: "If we want to win the competition, we need the whole team. And all the players need to be important."
Freeman, who scored his third goal for his national team, was over the moon to get himself on the scoresheet.
The full back said: "It was surreal... obviously at first it was disallowed, so I was kind of anxious when it went to VAR. It was so emotional for me because you dream of this moment."
He praised how his side dealt with missing their starman, saying: "It says that we have a really strong roster, and it says that whichever players we're going to put on the field, we're going to execute and be 100 per cent and get a result.
"Christian is such a vital part of this team, but if he's not available, someone else is going to have to step in."
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