"He was outstanding. I pointed out to him that if you're going up against a player who has got what you want then you need to put down a marker. He did that, as did Nick Kennedy, winning his battle with Simon Shaw."
Armitage, who began his rugby life as a centre before being convinced by his father to move to openside, was unashamedly honest about where he drew his motivation.
He said: "I knew Haskell, Rees and Worsley were all ahead of me in the England pecking order. I always want to smash a guy who has my shirt at the moment. They have my shirt and I wanted to outplay them.
"I knew that if I got to the ruck first, carried the ball strongly and stole my ball then it doesn't matter how well he [Rees] was playing. I knew if I got to the ruck first I'd be beating him.
"We put a lot of pressure on them. We put pressure on Haskell and he made a few errors and he's one of their main ball carriers. That's what won us the game."
Armitage played his way on to the England Saxons tour at the end of last season.
After losing 10 kilos because he was "bored of being called fat", further England honours look certain to come his way sooner rather than later.
For Irish the season looks bright, with Booth relishing the head coach's role after taking over from Brian Smith.
Evergreen Mike Catt is in charge of coaching the backs, although the 36-year-old still has plenty to offer on the pitch if Saturday's efforts are anything to go by.
Well looked after by Armitage, the fly-half pulled the strings effortlessly before being substituted midway through the second half with his job done.
Chris Hala'ufia and Richard Thorpe scored the Exiles tries while the Australian full-backPeter Hewat slotted six kicks from six.
Wasps director of rugby Ian McGeechan described his team's performance as "substandard" but refused to push the panic button after seeing his team claim the title last year after winning only one of their opening six games.
Elsewhere in the Premiership, Butch James inspired Bath to an impressive 33-20 win at Bristol and Leicester won at Gloucester.
Northampton were 21-13 winners at home to Worcester in their first game back in the top flight and Sale claimed their first away win over relegation favourites Newcastle.
