"Boof wants him to bowl for situations like this where it's flat," said fast bowler Ryan Harris, who himself took 3-43 in an outstanding return to test cricket. "He showed that when he gets it right, he is a dangerous bowler.
"We all know he has got talent. Darren has been forcing the issue for him to bowl."
The last time Smith played at the home of cricket, it was his debut as Australia's frontline spinner against Pakistan in 2010.
A leggie, Smith was billed as the next Shane Warne - and took 3-51.
Three years on, Smith returned to Lord's as a 24-year-old, with a new portfolio as a top order batsman and part-time tweaker.
However, in a startling spell on Thursday, Smith rediscovered his roots and is outstripping even Warne's impressive record at Lord's.
As it stands, Smith averages 11.5 at the venue, where six of his seven career wickets have come. Warne averaged 19.58 from four matches.
When Clarke threw Smith the ball in the 77th over, Ashton Agar was off the field with a minor hip injury and the tourists were on the back foot.
After England had been reeling at 3-28, Ian Bell (109) and Jonny Bairstow (67) were taking the game away from Australia.
The turning point had come earlier when fast bowler Siddle rattled Bairstow's stumps with the score at 4-171, only for the batsman to be called back when it became apparent Siddle had committed the cardinal sin of a front-foot no ball.
After Harris and Shane Watson (1-41) had England three-down early, the fifth wicket was necessary for Australia to capitalise.
Bairstow should have been in the pavilion for 21 - but instead Siddle's overstepping added 100 runs to the partnership and resulted in a withering spray from Lehmann at tea.
But Smith's late impact was immediate. After one full toss, he pitched a gem to Bell that spun and dipped, caught the outside edge, and floated safely to Clarke at slip.
Smith added Bairstow and Matt Prior to complete a blitz of 3-12 in 22 balls.
Viewed as a future national captain by selectors, Smith had already shown, in India and England, considerable improvement as a batsman. His bowling comeback is a bonus.
"He has a very good brain and captained NSW," said Harris, who played under Smith on the final game of the Australia A tour.
"He reads the game well. His batting has come on. The way he batted in the A tour I noticed he got better and better. He's in the bracket to be the next leader."
- AAP