World number 19 Ekaterina Alexandrova collapsed on court and was forced to retire from her first-round match at the Memphis Classic on Tuesday, as brutal on-court temperatures reaching 34C brought a dramatic and distressing end to what had been a marathon three-hour contest.

Alexandrova, the tournament’s top seed, was trailing 7-6 (7-2) 4-6 5-4 against 16-year-old Russian compatriot Kristina Liutova when the match unraveled. The warning signs had already appeared moments earlier, when Alexandrova struggled to serve and was handed a time violation for taking too long between points, a sign of how heavily the heat had begun to weigh on her. Then, in the middle of the following point, the 31-year-old sank to the ground and needed immediate medical attention on court.

She was eventually able to stand, but was in no condition to continue. Alexandrova retired just two points from the finish line, ending a match that had run for three hours and 11 minutes, and had to be helped off the court in a wheelchair.

The collapse handed Liutova, ranked 229 in the world, her maiden WTA Tour victory and her first-ever win over a top-20 opponent, on her main-draw debut no less. But rather than celebrating, the teenager was left in tears on court, visibly shaken by the chaotic scenes and comforted by her team as medical staff attended to her opponent. Liutova, last year’s Orange Bowl junior champion, is now just the second player born in 2010 to register a WTA Tour win, and will next face American Maya Joint in the round of 16.

The incident has reignited scrutiny over how the WTA Tour handles extreme heat during its North American hard-court swing, with several players in Washington and Tennessee having already voiced frustration over playing conditions in recent weeks. Under the tour’s heat policy, conditions of the kind recorded in Memphis, high temperature combined with heavy humidity, are meant to fall into a category that triggers stronger protective measures, including scheduled cooling breaks. In this instance, no formal cooling break followed the second set, and play continued uninterrupted until Alexandrova’s collapse forced officials to step in. Questions are now likely to be asked about whether existing heat protocols were applied as intended, or whether they need to be tightened further to prevent similar scenes.

This is not the first time Alexandrova has found herself at the centre of a heat-related incident on tour. Earlier this year, she was involved in an Australian Open match in which a ball girl fainted courtside in temperatures far lower than those recorded in Memphis, with Alexandrova and her opponent both rushing to assist before medical staff arrived. That episode, along with Tuesday’s collapse, adds to a growing list of instances underlining the physical toll extreme heat can take not just on players but on everyone on court.

Elsewhere on the WTA Tour, women’s tennis saw another notable result on Tuesday when 46-year-old Venus Williams was eliminated in the first round of the Mubadala DC Open in Washington. Williams, whose last singles win at the event came last year, lost 6-3 6-3 to Austria’s Anastasia Potapova. The veteran American won 78.4 percent of her first-serve points, a strong number on paper, but struggled badly on her second serve, winning just 24.1 percent of those points, while converting only 20 percent of her return opportunities, numbers that ultimately proved too costly against a more consistent opponent.

For Alexandrova, attention will now turn to her recovery and how soon she is able to return to competition, given that Tuesday’s retirement ended her Memphis campaign at the first hurdle despite entering the tournament as top seed. For the WTA Tour more broadly, the collapse is likely to keep the conversation around heat policy and player welfare firmly in focus as the North American hard-court season continues.