"I did know coming into the game I needed a couple of wickets," Leach said at stumps, with England's lead at 281 with five second-innings wickets remaining. "It was a nice feeling. The boys were always really happy for me. I was just pleased to get a wicket in that situation of the game, really.
"I just felt like, I don't know, 100 wickets feels like quite a lot. And it's more than I felt I'll ever achieve. I need to remember that. As sportsmen and as people, it's easy to just push on to the next thing and the next thing and the next thing, and nothing's ever enough."
"But if you told me that when I was a kid that I'd take 100 wickets, I would have laughed at you. So yes, it is special."
He became the 13th left-arm spinner to register 100 wickets for his country. But most impressively of all, the 50 innings it took to get here puts him in elite company: Wasim Akram, Chaminda Vaas, Shoaib Akthar, Rangana Herath, Mitchell Starc and Keshav Maharaj to do it in as many.
While Shakeel's wicket took him to 100, it was the next wicket of Mohammad Rizwan that was the most spectacular. Having been struck over his head for four, Leach got one to dip and spin off a leg-stump line and strike middle as the right-hander hung back and was beaten on the outside edge. A chip from Mohammad Nawaz to Stokes in close gave him four for the innings and took him to 102 across his career, at an average of 33.75.
"I'm just loving playing for England, the most I've ever loved it. And it's because it's all about the team, it's not about me. And that's a special feeling"
That Leach has achieved all this, not to mention playing in his 31st Test, is an indication of his resilience. He suffers from Crohn's disease, an inflammatory bowel disease, that was first diagnosed at the age of 14. It is managed with immunosuppressant medication, which weakens the immune system and thus leaves Leach prone to other ailments that could be life-threatening.
"I wouldn't think it would have been possible, just probably health-wise more than anything. I was quite close to not playing the first Test. There're lots of different challenges. I'm aware everyone has their challenges, I'm aware mine have been quite out there. That's good because I want to be open and honest with people. There've been some definite lows along the way, but it does sort of make it all worth it."
"Ben and Baz [McCullum] have a lot to do with that," he said when asked of his surer footing at international level. "But I think also just I've probably been learning on the job in Test cricket. I feel like I'm getting better and better, and learning more and more. It's nice to feel like I'm in control of what I'm doing. It feels good. Because if we're winning lots of games, then everything kind of takes care of itself.
"I feel like I'm just loving playing for England, the most I've ever loved it. And it's because it's all about the team, it's not about me. And that's a special feeling."
In the immediate future, he will have to play a prominent role in the ongoing second Test in Multan. The tourists boast a 281-run lead going into day three on a pitch spinning and now exhibiting indifferent bounce. Any victory, which would seal a famous series win with a match to spare, rests on him. For now, however, he is still coming to terms with breaking the 100-wicket barrier.
"I can't really believe it. I didn't think that would ever happen, so it's a nice, big milestone to get to." As for where he goes from here: "Just try and get another 100 now, I guess?"
Vithushan Ehantharajah is an associate editor at ESPNcricinfo