Viain has proved consistent through all three disciplines this season, finishing around the top 20 in World Triathlon Series events in Montreal and Edmonton.

Viain's former compatriot Felix Duchampt – currently in the process of switching to race under the Romanian flag – will also target glory this weekend, having won the Almaty Sprint Asian Cup earlier this month.

The course in Karlovy Vary starts with a 1.5 kilometres swim in Rolava Lake, ahead of a two-part bike course, consisting of a 6.5km ride into town and seven technical laps of the city.

It is rounded off with a four-lap 10km run.

The course could play into the hands of Austrian Lukas Hollaus, who narrowly missed out on a podium place in Nur-Sultan in June.

Czech star Vendula Frintová is favourite for the women's race.

She held off Estonia's Kaidi Kivioja for victory last year and will represent the ASICS World Triathlon team alongside Romina Biagioli of Argentina and Israeli Edda Hannesdottir.

Chelsea Burns and Tamara Gorman lead the United States' entries at Karlovy Vary, while Felicity Sheedy-Ryan returns for Australia.

She finished sixth in 2017, while team-mates Tamsyn Moana-Veale and Kelly-Ann Perkins will target podium performances.

Tenth at the Pan American Games last month, Ecuador's Elizabeth Bravo will be out to show that her fifth place in Huatulco was the start of another chapter in her long-running career.

Ukraine's Yuliya Yelistratova is seeking a first World Cup podium since winning gold in Huatulco last year.