VIDEO: England v Wales secretly taped
WATCH: It was meant to be a 'secret' session behind closed doors, but the cameras were rolling.
Lock George Kruis said England resisted the urge to "smash-up" Wales during Monday's unprecedented joint training session, in order to gain an insight into their set-piece strength.
However, forwards coach Neil Hatley revealed there was "a little bit of an edge".
Nigel Owens was called in to referee an unprecedented training session between the Six Nations rivals in Bristol on Monday.
The England scrum coach, Hatley, said there was no shortage of intensity and thinks both sides can reap the rewards ahead of the year-end internationals.
The secretly-taped video footage seems to confirm his claim of an intense session.
The Six Nations rivals completed 12 scrums and 16 line-outs over 40 minutes.
"There was definitely intent there," said Kruis.
"I'd say we were professional enough to control ourselves and understand it was a training tool rather than a smash-up on the Monday of a Test week."
"We went in there trying to get a squeeze on and as much out of it as we could. We wanted to win every scrum and wanted the intent, but it also gave ourselves the opportunity to trial a few things and see where we're at.
"It was under Test match intensity, but was a good tool for us. It definitely lets us know where we're at as a pack and has shown us things that maybe we need to work on for this week."
England play Argentina on Saturday, before Australia and Samoa visit Twickenham, knowing that come the end of November their record under Eddie Jones could stand at 22 wins from 23 Tests.
"It's tough sometimes training against yourselves because you know the calls, you know what they're going to do," said the England and Saracens lock.
"Wales didn't know what we were going to bring, it was reffed by a top quality referee which puts pressure on to your delivery and everything that comes with it.
"Argentina are a huge set-piece team and they had a good go at us down in Argentina in the summer, especially at the scrum, so there will be a huge focus on that."
Hatley said: "It was good, very worthwhile. Obviously it is good to get live competition early on in the week and it was a very worthwhile session, a lot to be gained from it.
"The way we’re trying to drive training, we want to make it as unbelievably competitive as possible, so I suppose it is the non-familiarity of it all - there were different players that you don’t scrummage against week in, week out.
"There was a little bit of an edge but nothing serious, I think both sides took a lot from it. It is a training aide to help us prepare for Argentina [on Saturday] so there was a good edge to it.
"We got what we were looking to get out from it with things that we’ve been looking at in Portugal and preparing for.
"Obviously everything is setting up to play against Argentina, who are a good set-piece team with a good scrum and line-out, so that is what today was handy for.”
England have yet to rule Elliot Daly out of the series opener against the Pumas.
Daly injured his knee on Champions Cup duty for Wasps and was expected to miss the Tests against Argentina and Australia and potentially return for the last Test, against Samoa, but he could yet be involved from the start.
England are in the midst of a wing injury crisis having lost Jack Nowell and Jonny May to the treatment room, making Daly's availability, should he be passed fit, welcome news for Jones.
England scrum coach Neal Hatley said: "Elliot is in camp and being assessed. We've been pretty busy so we'll find out more about him later in the day."
Warren Gatland's Wales play Australia on Saturday and have further matches against Georgia, New Zealand and South Africa.
Sources: AFP & RugbyPass