England head coach Eddie Jones bemoaned an error-strewn performance after his side handed Argentina a first win at Twickenham for 16 years on Sunday.
The match turned on two Pumas tries in the space of four minutes early in the second half, first from Emiliano Boffelli and then Santiago Carreras.
Joe Cokanasiga and Jack van Poortvliet touched down for England in a kick-heavy Autumn Nations Series opener on a sodden surface in south west London.
Jones called the display “not good enough”, adding: “Losing always hurts. It was one of those games, the lead changed a lot.
“You can’t put your finger on what went wrong. Structurally we had control of the game but we kept making fundamental mistakes and easy errors.
“Congratulations to Argentina, they took their chances and stuck in the game. We have no excuses, the referee, the pitch was the same for both teams.
“After half-time we were getting our game in place, we were looking fluid in attack but then we made mistakes and we were chasing our tail.
“We made silly mistakes but I like the way the team went about it. We didn’t finish well. There was a lack of cohesion.”
Replacement scrum-half Van Poortvliet’s improvised try, just 29 seconds after coming off the bench, was a rare bright spot on a grey day for England.
Owen Farrell, who registered 19 points, converted but the hosts could not find another breakthrough as the two teams traded penalties.
This clash with Argentina was a dry run for England’s pool stage opener at next year’s World Cup in France.
Jones now has five days to engineer an improvement in their next game against another side they will face at the tournament, Japan, on Saturday.
The Pumas, meanwhile, were celebrating another major scalp just three months after beating the All Blacks in New Zealand.
They were happy to give up the lion’s share of possession – they had just 37 per cent at Twickenham – and rely on staunch defence and counter-punching.
“We were able to take points even though we didn’t have a lot of ball,” said coach Michael Cheika.
“The players have got a great attitude. They need to know what defence is – it’s not about a great ending, it’s about getting a good field position so you are able to pounce.”
The Carreras try aside, all of Argentina’s points came from Edinburgh wing Boffelli, who kicked six penalties and two conversions.
“We said at half-time that we must stay close in the score, then we got two tries,” he said.
“Our attitude was important. The coach – everyone knows him as a coach and he has great experience. He is confident in us. To score 25 points at Twickenham is great. The whole team did their job.”