Garbine Muguruza overcame Aryna Sabalenka in a tight three-setter for a second consecutive week to storm into the Dubai semi-finals for a third time in seven appearances.
The Spaniard, a runner-up in Doha last week, bounced back from a set down to eliminate the third-seeded Sabalenka 3-6, 6-3, 6-2 and set up a showdown with Belgium’s Elise Mertens.
Earlier on centre court, Mertens, the No.10 seed, pulled off a miraculous comeback, saving three match points en route to a 5-7, 7-5, 6-0 success over Jessica Pegula.
The world No.18, who was down 5-7, 2-5 before she turned things around, is into the 15th tour-level semi-final of her career.
"It's unbelievable to come back like this. I just didn't want to let it go, I just kept on fighting, and I think that was the spirit today," said Mertens.
Muguruza and Sabalenka provided one of the best showdowns in Doha last week and brought more of the same in Dubai on Thursday.
The rallies were explosive from the get-go as the pair exchanged 140km/h forehands and unleashed one massive groundstroke after the other.
Sabalenka earned the first break of the match to open up a 4-1 gap and it was enough for her to secure a one-set lead in 35 minutes.
Muguruza was broken at the start of the second but rebounded immediately, taking the next four games and she soon levelled the match.
Breaks were traded early in the decider before Muguruza went up a double-break 5-2 lead as Sabalenka unravelled.
- 'Slow enough' -
The former world number one served out the win comfortably to squeeze into the final four for a second time in as many weeks.
"I was expecting a tough battle and I was ready for it. She played great in the first set, I think I was, not slow, but slow enough to give her the dominance," ninth-seeded Muguruza said.
"I wanted to come back stronger in the second set and I went for it," she added.
Pegula, one of 15 main-draw debutants in Dubai this week, entered the quarter-finals having dropped just eight games through her first three rounds in the Emirates.
The 26-year-old American backed up her breakthrough run to the Australian Open last- eight by making the semis in Doha last week prior to her arrival in the UAE.
Mertens, 25, is already a title winner this season, having picked up the Gippsland Trophy in Melbourne last month, and is 11-1 win-loss in 2021.
She served for the opening set at 5-4 after claiming a crucial break of serve with a stunning backhand passing shot winner, but dropped the next eight points as Pegula grabbed the 75-minute set on a costly double fault.
Pegula leapt to a 4-1 advantage in the second but was broken at love while serving for the victory at 5-3.
Mertens saved three match points in the next game and stole the set to force a decider.
Pegula never recovered as Mertens claimed the last 11 games of the match to punch her ticket to the final four.
Meanwhile, the 63rd-ranked Barbora Krejcikova reached the biggest semi-final of her career with a dominant 6-0, 6-2 victory over Russian teenager Anastasia Potapova.
Krejcikova, a former doubles world number one, has enjoyed an impressive week so far, taking out 16th seed Maria Sakkari and Grand Slam champions Jelena Ostapenko and Svetlana Kuznetsova en route to the last four.
She next faces Switzerland's Jil Teichmann, who defeated Coco Gauff for the first time in their third meeting of the season, 6-3, 6-3.