Two remarkable Italian women in their 30s, Roberta Vinci and Flavia Pennetta, upset all the odds to defeat the two highest-ranked players in the world – Serena Williams and Simona Halep – and set up the most unlikely of US Open finals.

Vinci, 32, held her nerve in a pulsating three-set encounter with Serena, producing the best tennis of her career in the crucial moments during sets two and three to win them both by the same score, 6-4, after being overwhelmed by the American’s powerful hitting in the opening set.

Before the match, the Italian world No. 43 had never reached the semifinal stage of a Grand Slam singles tournament and had never even won a set, let alone a match, against the world No. 1. Very few people believed she had any chance of ending Serena’s hope of achieving an historic calendar Grand Slam.

The American superstar made light work of the first set, winning it 6-2, and looked to be heading into the final with few alarms. But suddenly Serena seemed to be feeling the pressure, and she just barely held her serve in a nervous opening game of the second set. Perhaps Vinci noticed this and sensed an opportunity, since she charged up to the net in the fifth game of the set to hit a smart volley and put pressure on the Serena serve. Soon she had break point at 30-40, and Serena cracked, netting a relatively simple backhand.

Vinci sensibly worked Serena all around the court for the remainder of the set as she successfully held three times to take it 6-4. She then proceeded to make the visibly tired top seed run even more in the third set, and was rapidly looking, incredibly, like the player who was most likely to win the match. After trading breaks with Serena early on in the set, Vinci earned the decisive break in the seventh game after playing one of the points of 2015. She dragged Serena to from side to side and back to front before coming into the net to seal it with a precise volley. That gave her a break point, and a wound-up Serena handed her the break with an error.

The veteran Italian then held serve to lead 5-3, despite serving consecutive double faults in that game, and suddenly Serena was serving to stay in the match. She won the game with the help of two emphatic aces, but Vinci was not to be denied. She played four excellent points to hold to love and clinch the most amazing victory of her life.

Her compatriot Flavia Pennetta also played superbly to beat a woefully below-par Simona Halep 6-1 6-3 in a one-sided semifinal and book her place in her first-ever Grand Slam final at the age of 33.

Every part of the Italian’s game looked to be in good working order as she served well, returned aggressively and effectively, and struck significantly more winners (23) than unforced errors (16). By contrast, Halep won less than 40% of the points on her serve, was broken six times, and made 23 unforced errors in a match she lost in just 59 minutes. It was another example of her worrying tendency to go missing during the biggest occasions in her career – a tendency her fans hoped was behind her.

The match started routinely, with both players winning their opening service games, but the rest of the opening set was very much a Halep horror show. The Romanian made 14 unforced errors and surrendered her serve twice as her game totally fell apart. All Pennetta had to do most of the time was make Halep play and wait for her to make an error.

A third break for Pennetta at the beginning of the second set seemed to spark the world No. 2 into life. She hit a couple of thumping backhand winners down the line as she won three games in a row. But all that Halep’s brief resurgence ultimately did was bring the best out of her Italian opponent, who raised her game to a very high level in response, hitting an exceptional 16 winners during a vintage second set as she reeled off five games in a row to seal her place in the final.