Looking to avoid a third league match without victory at home to modest Huracan on Sunday, they were level at 1-1 when the sprinklers suddenly came on all over the Monumental pitch with seven minutes to play.
Coach Marcelo Gallardo, whose side were pushing for a winning goal, looked angrily towards the sky as if seeking a culprit when there did not appear to be one, just a mechanical fault.
Referee Saul Laverni stopped play until the sprinklers were turned off less than two minutes later and Gallardo ended up laughing.
“It was very funny,” he said.
However, River have slipped 11 points adrift of leaders Boca Juniors in fifth place, although they do have a match in hand.
“I’m angry at not being able to round off all the good we generated,” said Gallardo, whose side will play in the Club World Cup in December after winning the Libertadores Cup.
“There was only one team on the pitch in the first half, we scored one goal and could have got another but lacked finishing,” he told a news conference.
Midfielder Gonzalo Martinez opened the scoring for River after a quarter of an hour and Daniel Montenegro equalised five minutes before halftime.
“This match was important because we couldn’t keep dropping points at our ground,” said Gallardo, whose side were upset 1-0 at home by San Martin two weeks ago and lost 2-1 at Estudiantes last weekend.
They will be without four players on international duty, Argentina’s Matias Kranevitter, Uruguayans Carlos Sanchez and Camilo Mayada and Eder Alvarez Balanta of Colombia, for next weekend’s match at joint bottom Nueva Chicago.
(Writing by Rex Gowar, editing by Ed Osmond)