Malan, playing his eighth Test, knew he needed to provide a substantial innings to sustain both his own career at this level and England's hopes of retaining the Ashes. Shortly after he came to the crease, England were 131 for 4 and facing the prospect of squandering first use of a pitch that may offer bowlers pace and bounce, but also looks full of runs.
But in partnership with Jonny Bairstow, Malan saw England through to the end of play. Despite conceding he had to look away when England's opener, Mark Stoneman, sustained a crushing blow to the side of the head, Malan led the way as the pair produced not only their side's highest partnership of the series to date - an unbroken 174 for the fifth wicket - but took them to their highest total so far.
While England's batsmen still have work ahead of them on day two - their bowlers could struggle to find much encouragement from this surface - Malan and Bairstow's efforts represented perhaps England's best day of a tour in which they have tended to make the headlines for the wrong reasons.
Rendering the occasion all the more special for Malan, he played the innings in front of his parents, Dawid and Janet, who had flown in from South Africa to watch him. He pointed his bat in their direction upon reaching three figures and hugged his mum as he left the pitch at the end of the day.
"It was so emotional, I didn't really know what to do," Malan said afterwards. "I almost started crying when it happened.
"To make my maiden Test century in front of my parents after the amount of sacrifices my old man and mum made for me made it very special. It's nice to repay them for all the time they've given me."
Reflecting on the off-field issues that have dogged England's tour, he said: "We made the headlines for the wrong things and the only way to put those things to bed is to win games of cricket. We're in a position now when we've got one foot in the door and we need to capitalise on that on day two."
Malan concedes there were moments during the first few weeks of his Test career when he doubted he was good enough to make it. Feeling he was picked for his Test debut in July just as he had lost a bit of form, his first innings brought him just one run and ended when Kagiso Rabada both bowled him and knocked him off his feet with a perfect yorker. After his first four innings yielded just 35 runs, he feared he may be dropped.
But now, with a century behind him, he hopes he has proved to himself he belongs at this level.
"After those first two games, I never thought I'd score a run in Test cricket to be honest," Malan said. "It was quite tough. But I've adjusted my game here and there to work at Test cricket.
"I was under a bit of pressure coming into the game. And there was a tough period at the start of my innings and then another about an hour later. In other innings I've felt comfortable but given it away. Here I was ruthless. It was especially nice to get some runs when the team needed it.
"It's good to put the doubts to bed. We always felt we have the backing from the coach and captain, but every time you open the newspaper you read how poor you are and how bad you are. So it's nice to tick a box and prove to yourself you can play at this level and score hundreds.
"Anything you do is about self-belief. You need to prove to yourself you belong. When you get that first hundred or first five-for, you have the belief to trust your game going into the next match. It doesn't mean you'll be successful, but you have the belief you need to perform at the highest level."
He endured a couple of nervous moments, most notably when he was dropped on the slips on 92, but says he generally relished the pace of the bowling and the challenge it offered.
"I got a bit ahead of myself there," he said. "I knew I was two or three shots away from scoring a hundred and premeditated my shot a bit. I thought the ball would be full, so I set up to clip through midwicket but it swung away a bit. It was a good time to have a let-off. It put me back in my box.
"When I saw Mark Stoneman hit on the head, I wanted to walk away and have a chat with someone in the back of the dressing room. But I've really enjoyed the pace that these guys bowl. When you play county cricket you're more worried about being nicked off with 78mph dibbly dobblies, so I've really enjoyed the challenge. It tests you in different ways: not only technically but your heart as well.
"Now we need to capitalise on the moment. We need to put as much pressure on them as we can and score as many as we can. That first hour will be crucial and if we give them a sniff, we're going to be on the back foot."