One week after losing to Karen Khachanov in Adelaide, the 21-year-old Briton snapped back at the same venue with a 6-4, 7-6(3) win on Thursday at the Adelaide International 2.
The victory earned Draper a spot in his second ATP Tour semi-final, where he will take on South Korea's Soonwoo Kwon.
Aggressive from the first ball with his first-strike tennis, Draper saved the only break point he faced until he stepped to the line to serve out the match at 5-4 in the second.
After a loose game gave new life to the third-seeded Khachanov, a visibly frustrated Draper regrouped to finish the match in straight sets.
"In the last game I got a bit nervous, but that's part of the game," the lefty said in his on-court interview. "I'm still young, I'm still learning from these things."
The crucial point of the tie-break came at 2-1, when Draper defended from corner to corner, ultimately drawing an error to claim a mini-break. This time he would not let the lead slip, mixing in a serve-and-volley to close out a tie-break in which he won all five of his service points.
"Against guys like Karen, you can't give them an inch, otherwise they run away with it," Draper said after earning his first ATP Head2Head win in three tries against Khachanov. "He plays so aggressively and serves really big. Off the back of the court he looks to be on the front foot, and if you're not willing to try and get up there with him, he takes charge of the game. I did well to impose my game a little bit more today than last week."
Draper's win against the World No. 20 comes after two Top 10 victories last season over Stefanos Tsitsipas (Montreal) and Felix Auger-Aliassime (US Open). Entering the week at a career-high of No. 40 in the Pepperstone ATP Rankings, the Briton will look to continue his rise in his semi-final matchup against lucky loser Kwon, who booked his own semi-final place with a comfortable 6-1, 6-2 victory against Mikael Ymer.
In the top half of the draw, Roberto Bautista Agut dominated an all-Spanish quarter-final against Alejandro Davidovich Fokina to claim a semi-final berth. The fourth seed did not face a break point in his 82-minute 6-3, 6-2 victory, while breaking his countryman’s serve four times.
Bautista Agut has a strong track record when it comes to performing in the early weeks of the ATP Tour season. The 34-year-old has won four of his 11 tour-level titles in the month of January, and he will look to move one step closer to a fifth when he meets Miomir Kecmanovic or Thanasi Kokkinakis in the semi-finals.