The draw had handed the 21-year-old rising British star a blockbuster clash with his childhood idol on his debut at Melbourne Park, and an opportunity to really break through onto the world stage given Nadal's poor form.
A run of six defeats from seven matches heading into the year's first grand slam was the worst of his career, and there were plenty of uncharacteristic errors before Nadal ground out a 7-5 2-6 6-4 6-1 victory.
Draper looked capable of causing the upset when he took the second set on Rod Laver Arena but physical struggles have hampered his career so far and he began to cramp in the third set before hobbling through the final stages.
No one is more aware than Draper that a lot of off-court work is needed before he can start to reach his potential, and he revealed most of his pre-season was wiped out by two periods of illness.
"Going to this trip in Australia, I was very undercooked, to be honest," he said.
"After last year, I was really excited about doing a good pre-season. I had two viral infections so had to be on antibiotics on two occasions. I lost five of those seven weeks.
"I've got to be proud of the way I competed in Adelaide (he reached the semi-finals of the ATP event there last week) and the effort I put in there. I think I surprised myself with where I've been at.
"Obviously this physical thing is going to take time. It's going to take patience. But I'm fully aware of that and I'm willing to do everything I can to put myself in a great place moving forward."
Draper copied Nadal's look as a child but also modelled his game around his hero, including playing left-handed even though he is naturally right-handed.
The influence is clear in Draper's heavy topspin forehand and solid backhand hit predominantly cross-court but occasionally, and explosively, down the line.
Draper made his Wimbledon debut against Novak Djokovic on Centre Court in 2021 so this was not an entirely unfamiliar situation, although his ambitions were significantly higher this time.
Nadal was solid enough in the first set, taking advantage of a couple of poorly executed drop shots from Draper, but the momentum shifted at the start of the second.
Draper broke the Nadal serve for the first time from 40-15 and capitalised on a slew of errors from his opponent to move 4-0 in front.
He could even have won the set 6-0 but showed no hesitation wrapping it up and the match was in the balance until he began to cramp in the fourth game.
Still Nadal was shaky but Draper's serve and groundstrokes now lacked the necessary weight and, although he broke again to open the fourth set, his body gave out on him completely half way through.
Draper, who recently hired a fitness coach in Croatian Dejan Vojnovic, said: "I felt at the beginning of the third that my tennis was right there. I almost felt like I was in control of the match at that point.
"The first set's always tough. I've never been on court with Rafa before. The second set, I sort of calmed down and started playing really well. If I would have carried on that way, who knows?
"I just need to investigate why I'm getting (cramp), but also know that I've only just started really with my fitness trainer that I've invested in.
"Obviously playing a player like Rafa on Rod Laver, something that I'll remember for a very long time. A real honour to play against him, someone I've idolised growing up.
"To go toe-to-toe with him on a big court like that is special. I think I can take away the fact that my tennis is getting closer and closer."
Draper earned positive words from Nadal, who said: "He's a great player with a lot of potential, young. A great future in front, I think. So it was a tough, tough match. Full respect for him. Wish him well for the future."