Paine, who took over from Smith as Australia's captain last year, in the wake of the Cape Town ball-tampering scandal that led to Smith's year-long ban from cricket, admitted to being in awe of his talents, after a haul of 671 runs in five innings peaked with his scores of 211 and 82 at Old Trafford.
"He's pretty handy, I won't lie," Paine said during the post-match presentations. "He's the best player I've ever seen. Obviously his 200 was phenomenal but yesterday to push the game forward put England under pressure. He's got a lot of courage to take teams on."
Paine himself contributed an important half-century in partnership with Smith in the first innings, but has now secured himself a place in Australian folklore as the first captain to retain the Ashes in England since the great Steve Waugh in 2001.
And seeing as, two winters ago, Paine had been contemplating his retirement from professional cricket after receiving an offer of a full-time role at the bat-makers, Kookaburra, the turnaround in his fortunes was doubly hard to quantify.
"It's a very funny game," he said, "even half an hour ago [during England's ninth-wicket stand] I was thinking I should have taken that job. I'm really humbled to come here as captain and do something really special. We'll enjoy tonight but we came here to win them, not just to retain them. We'd love to be 3-1 up when we hold the urn aloft."
"I'm pretty pumped," he added. "This team has been through a lot in the last 12-18 months. Some individuals more than others. The character we've shown to bounce back, even from Headingley last week, shows a lot about the quality of the people.
"It's been an unbelievable series, I've not had too much sleep during the Tests. It's been intense. Every game has gone down to the wire. That's what you expect and prepare for."
The key moment on the final afternoon came when Paine turned to the part-time legspin of Marnus Labuschagne, who prised out the obdurate Jack Leach with the final hour of the match approaching. He described that decision as a bit of a "guess", but paid tribute to the manner in which his players had held their nerve.
"I was really proud the way our bowlers kept sticking at it as they have all series and we said we'd get our rewards late," he said. "Sometimes I didn't believe it but today we did.
"We tried to stay calm, not always easy when it means so much to everyone and everyone is so invested in it. I thought we handled it pretty well, and the whole week coming out of Headingley. I'm really pumped the boys got what they deserved."
Reacting to the loss of the Ashes, a crestfallen Joe Root said: "I thought we showed great character today, I couldn't be more proud of the effort. As last week we always believed, we fight right to the end. We tried our hardest.
"We had some fantastic support, so it's bitterly disappointing. But we've got to make sure we turn up for what's still quite a big game at The Oval."