There was also lineout practise between the two packs - overseen by Welsh referee Nigel Owens - as England readied to face Argentina on Saturday and Wales prepared to host Australia.
“There was a little bit of an edge but nothing serious,” said England scrum coach Neil Hatley of the morning session as the two packs practised against each other, looking ahead to a month of internationals mainly against southern hemisphere opposition.
“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," 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,” he told reporters.
The idea was proposed by England assistant coach Steve Borthwick and backed by Wales coach Warren Gatland.
"It shows the spirit of rugby that can put your hat on one side and do it for the greater good of northern hemisphere rugby,” Wales defence coach Shaun Edwards said.
(Reporting by Mark Gleeson,; Editing by Ed Osmond)
