England's unprecedented joint training session with Wales had "a bit of an edge" and was "massively beneficial", says scrum coach Neal Hatley.
English and Welsh forwards trained behind closed doors in Bristol on Monday in preparation for their respective autumn internationals.
England play Argentina at 15:00 GMT at Twickenham on Saturday, with Wales facing Australia in Cardiff at 17:15.
"This was about getting ready for Argentina," Hatley told BBC Sport.
"I don't think you can say who won, today wasn't about winning," he added.
"Sessions like this have a tendency to develop into a bit of a bundle but it was well managed. We want to make sure even when we scrummage amongst ourselves there's an edge.
"We are pleased with what we did, probably on 80% of our ball, and on their ball. It was a good session. It forces you to grow. If people know what you're doing you have to keep finding the next edge."
Wales and England completed 12 scrums and 16 line-outs over 40 minutes to hone their set-pieces.
"There was a good bit of bite to it," England lock George Kruis told BBC Sport.
"Nothing boiled over but there's a lot of history between us and we definitely got the most out of it.
"Our main focus was getting better as a pack for this weekend. It was definitely worthwhile."
World Cup 2015 final referee Nigel Owens, who officiated the session. said it was a "pretty even contest".
"They were full-on, competitive scrums you would see in an England and Wales Six Nations match," said Owens.
"On a couple of scrums England were quite strong and then Wales were quite strong, so it was evenly contested.
"They play hard and fair when they go out on the field and they did exactly the same today."
After their game against Argentina, England host Australia on 18 November and Samoa on 25 November.
Wales play Georgia on 18 November, New Zealand on 25 November and South Africa on 2 December.