The talented 19-year-old Queenslander, fresh from winning her first ever match at WTA 1000 level the previous day, gave world No.10 Emma Navarro all the trouble she could handle before going down 7-5 7-5 to the American in Thursday's second round at the Caja Magica.
Matching the American clay-court expert shot for shot, it was only Joint's inexperience and nerves at the business end of both sets that separated her from the in-form Navarro, who won a tournament in Mexico last month.
At times, Joint's clean, powerful striking had the New Yorker on the run and she will look back with a touch of frustration on a first set which she largely dominated until throwing in a poor service game at 5-6 when she coughed up three doubles.
Navarro also fund it hard to subdue the effervescent qualifier in the second set as Joint kept up the fight, hitting back from 3-1 and 4-2 down only to eventually succumb with a couple of wayward backhands when serving to take the stanza into a tiebreak.
But this was another excellent performance from Joint, who won three matches in three days before finding Navarro a hurdle too far on the fourth.
Still, only five points (85-80 to Navarro) separated the teen from the US Open semi-finalist over a one-hour 47-minute battle which only emphasised the pace of Joint's improvement over the past year-and-a-half since she began 2024 ranked the world No.684.Â
Now at 78, her ranking is just soaring only one way and this performance on the clay suggested she could be a handful in what will be her second grand slam outing at the French Open next month.
But her exit means there's only one Australian left in the women's field, with 14th seed Daria Kasatkina set to open up, in just her second tournament representing the green-and-gold, against American Alycia Parks in Friday's second round.
Joint is one of only three teenagers in the world's top 100, and the other two also both impressed on Thursday with 19-year-old Alex Eala giving defending champ Iga Swiatek another scare before going down 4-6 6-4 6-2 to the world No.2 on the Manolo Santana Stadium court.
Swiatek was relieved to gain revenge over the Filipina left-hander who had beaten her in a sensation at the Miami Open last month on her way to the semi-finals and seemed in a position to repeat the dose after taking advantage of the Pole's sluggish start to take the first set.
It was the best of the top-100 teens, world No.7 Mirra Andreeva, who showed the other two how to do it as she breezed past Czech Marie Bouzkova 6-3 6-4.
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