Swiatek became known as the ‘Queen of Clay’ as she gained a firm grip on Roland Garros, winning four titles between 2020 and 2024, as well as six WTA Tour events on the red dirt.
However, she lost her invincibility on the surface last year – unable to win a clay-court tour event before losing in the Paris semi-finals.
Swiatek tweaked her playing style under previous coach Wim Fissette, who tried to implement a more aggressive approach from the baseline.
But she ended up losing confidence in what they were trying to achieve and quickly became ragged when matches started going against her.
It has been a case of going back to basics with Roig, who she snapped up after his short stint with Britain’s Emma Raducanu ended.
Swiatek played with the high intensity and relentlessness demanded by Roig from the start against Pegula – but, crucially, she always looked stable in her shot-making.
Playing with more patience and a higher margin for error meant she was able to draw mistakes from the 2024 US Open finalist.
Pegula was well below par on a surface she does not favour, but the manner in which Swiatek refused to let her level drop was a sure sign of her increasing assurance.
Swamping Pegula’s second serve with deep returning was another notable feature.
Tougher challenges will surely lie ahead in Rome. Swiatek will face Elina Svitolina in the semi-finals after Ukraine’s seventh seed recovered to beat Kazakhstani second seed Elena Rybakina 2-6 6-4 6-4, but the signs for her French Open challengers are beginning to look ominous.
In the men’s event, Norway’s Casper Ruud beat Russian Karen Khachanov 6-1 1-6 6-2 to reach the semi-finals, where the world number 25 will face Italy’s Luciano Darderi or Spain’s Rafael Jodar.
Meanwhile, Italian world number 10 Lorenzo Musetti has become the latest leading men’s player to withdraw from the French Open through injury.
Musetti reached the Roland Garros semi-finals last year but has been ruled out with a thigh problem picked up in Rome, joining Spain’s defending champion Carlos Alcaraz and Britain’s Jack Draper on the sidelines.