World number one Aryna Sabalenka's clay-court season hit another speed bump on Monday, as she suffered a second defeat in three matches—this time at the hands of Romania's Sorana Cirstea in the Italian Open third round. The 6-2, 3-6, 7-5 loss in Rome marks an uncharacteristic stumble for the Belarusian powerhouse, who had been dominating the tour with 17 consecutive quarterfinal appearances or better.

Just 11 days after squandering six match points in a Madrid Open quarterfinal loss to Hailey Baptiste, Sabalenka's French Open preparations are now under scrutiny. The 28-year-old, who has never won the Italian Open title, showed flashes of brilliance but ultimately struggled to close out key moments. She was twice a set and a break up against the 36-year-old Cirstea, who is retiring at the end of the season, yet couldn't maintain her grip on the match.

Sabalenka's serve—widely considered the most improved weapon in her arsenal and the foundation of her rise to world number one—was broken six times. While she landed 72% of her first serves, she won only 56% of points behind it and just 11 of 26 points on her second serve. The inconsistency proved costly, especially after she broke Cirstea when the Romanian served for the match at 5-4 in the third set, only to immediately hand the advantage back.

Frustration boiled over late in the match as Sabalenka slapped at a ball after losing five straight games to drop the second set and fall behind early in the decider. She called for a medical timeout for treatment on her lower back at 4-3 down, but despite briefly mounting a comeback, a wide forehand on match point sealed her fate. The loss ends her streak of reaching at least the quarterfinals in 17 consecutive tournaments—a run that stretched back to February's Dubai Championships.

For Sabalenka, the Italian Open exit means she heads into this month's French Open with just four wins and two losses on clay. Last year, she fell to Coco Gauff in the Roland Garros final in what she called "the worst final I ever played," committing 70 unforced errors. With the season's second major fast approaching, the world number one will need to rediscover her rhythm—and her serve—if she hopes to finally claim the title that has eluded her.