Boris Yotov, pictured competing for Azerbaijan, was among qualifiers today after switching nationality ©Getty Images

Boris Yotov provided the home highlight on the opening day of the World Rowing Under-23 Championships in Plovdiv after safely progressing through the heats of the men's single sculls.

The 21-year-old represented Azerbaijan at last year's Olympic Games in Rio de Janeiro before switching to his country of origin.

He finished third in heat two after surging through in the late stages to qualify behind Canadian heat winner Trevor Jones.

Romania’s Marian-Florian Enache, Germany’s Marc Weber, Italy’s Salvatore Monfrecola and Natan Wegrzycki-Szymczyk of Poland were other heat winners on the Maritsa River.

On a sweltering opening day of competition, temperatures reached 30 degrees at a venue also due to host the 2018 World Championships.

More than 800 rowers from 54 countries are competing.

European rowers were the most dominant, although oarsmen and women from Australia and United States led the international charge.

Romania, Italy and The Netherlands were the three heat winners in the new Olympic women's coxless four event.

Australia, Britain and The Netherlands crossed the line first in the three heats of the corresponding men's event.

Only two automatic final spots were available in the women's coxless pairs heats.

Kendall Brewer and Brooke Pierson took the first for the US and Annabelle McIntyre and Bronwyn Cox claimed an Australian win in the second.

The competition is scheduled to last until Sunday (July 23).