Slovenian qualifier Kaja Juvan caused the biggest upset of the day on Tuesday at the WTA Palermo Open, the tournament marking tennis’ return to action after five months from the Covid-19 pandemic.

Juvan battled to beat second seed and French Open runner-up Marketa Vondrousova of the Czech Republic 1-6, 7-5, 6-4 in the first round of the clay-court event. It was the 19-year-old’s first Top 20 victory and came after a battle lasting two-and-a-half hours.

Top-seeded Petra Martic had a much easier outing as she reached the second round with a 6-0, 6-3 win over Alison Van Uytvanck. The Croatian will take on Russian qualifier Ludmilla Samsonova, who beat Kirsten Flipkens 6-4, 6-2.

Fifth seed Elise Mertens was beaten 6-4, 6-1 to Belarusian qualifier Aliaksandra Sasnovich while fourth-seeded Anett Kontaveit rallied to beat Patricia Maria Țig 6-3, 6-3. Camila Giorgi, the former world No 26, also fought back from a slow start to beat Rebecca Peterson, 7-5, 6-4, and advance to the second round.

Third seed Maria Sakkari was knocked out on the first day by Kristyna Pliskova.

The tournament in Italy marks the return of tour-level tennis following a five-month break for the coronavirus pandemic.

The event comes just weeks before the US Open and Roland Garros double-header but lost original top seed Simona Halep to lingering health concerns while an unnamed player withdrew from qualifying after testing positive for coronavirus.