Smith's surprise elevation ahead of the explosive Warner paid immediate dividends as Australia tentatively opened their Ashes campaign at Trent Bridge.
With the tourists facing a humiliating end to a day which had started so brightly, Smith became the unlikely saviour when the top four had failed.
Thrown on the scrapheap just three years ago, the hallmarks of Smith's rapid redevelopment as a Test player were all on show on Wednesday as he aggressively took on spinner Graeme Swann, plundering five boundaries and a six, and withstood the pace barrage from Jimmy Anderson and Steve Finn to be unbeaten at stumps.
"(He was) just playing his own game which we encourage," Australian coach Darren Lehmann said.
The 24-year-old was once viewed as the future of Australian cricket, earning a $1 million CA contract as he blasted his way into the national side in all three forms of the game.
But less than convincing displays in his first five Tests led to the youngster being banished from the Test team for more than two years - and an overhaul of CA's player contract system.
While coming to grips with the growing perception that he was now a designated short-form cricketer, Smith embarked on a mission to reinvent himself.
It involved abandoning his leg-spin and focusing entirely on returning to the Test side as an out-and-out batsman.
On the surface his Sheffield Shield season of 296 runs at 37 doesn't sound worthy off a Test recall, but selectors saw a refined technique and a player who put a price on his scalp.
And with wickets tumbling around him and an England attack sensing blood in the water, Smith stood tall - allowing the selectors to release a small sigh of relief at one bold selection which has come good.
"I thought he played really well for a young guy in his eighth or ninth Test match so really pleased with how he handled it," Lehmann added.
"(They were) tough conditions."