Eva Samkova moved to the top of the women's overall standings with her second World Cup snowboard cross win of the season, in Bakuriani, Georgia.
Having already triumphed in Chiesa, the Czech Olympic and world champion prevailed in a four-way fight, beating France's Julia Pereira de Sousa Mabileau and American Lindsey Jacobellis into second and third.
The win leaves Samkova five points clear of Italy's Michela Moioli, who finished fourth on the day, on 305 points at the top of the standings â€“ with the two destined for a standoff over the final two races â€“ while America's Faye Gulini is third on 222.
Murase and Boesiger win first Big Air World Cup events of the season
Britain's Charlotte Bankes, who beat both Samkova and Moioli to World Championship gold last month, came home fifth.
"It was so tough and really difficult, because the girls were riding amazingly," Samkova said.
"And I put my 150% in all of the runs, but especially in the final. It was really hard, super tight and my legs are really burning, so I am super happy that I made it, but also congrats to all the girls!"
Meanwhile, Canadian Eliot Grondin continued his fine form as he captured his maiden World Cup win in the menâ€™s equivalent event.
The 19-year-old claimed a first World Championship bronze medal last month and has now followed that up with a maiden World Cup triumph, beating Austria's Lukas Pachner and Italy's Lorenzo Sommariva.
The victory moves Grondin to within eight points of overall World Cup leader Alessandro Haemmerle, on 270 points, with Dutch star Glenn de Blois third on 187.
"In my first heat, I almost didn't make it, it was super tight, but after that I figured out my strategy for the race and then I knew that I could win the start in the big final and let people pass me. And that's what I did," Grondin said.
"Alessandro [Haemmerle] passed me and then also Lorenzo [Sommariva], and for me it was the perfect situation to draft and pass for the finish."
16-year-old Murase claims stunning win at big air event in Chur
‘He finally gets on the top step of the podium!’ – Boesiger claims big air success in Chur