Neil Hatley revealed there was "a little bit of an edge" when the England and Wales forwards faced each other in what he said was a worthwhile exercise for both parties.
Nigel Owens was called in to referee an unprecedented training session between the Six Nations rivals in Bristol on Monday.
England scrum coach Hatley said there was no shortage of intensity and thinks both sides can reap the rewards ahead of the autumn internationals.
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 lineout, so that is what today was handy for."
Photo Getty Images. Caption: England scrum coach Neil Hatley