Second seed Agnieszka Radwanska easily won her semi-final at the Tianjin Open on Saturday, setting up a final against unseeded Danka Kovinic of Montenegro.

Poland’s Radwanska, ranked world No.6, beat third-seeded Czech Karolina Pliskova 6-3 6-1.

Kovinic beat Bojana Jovanovski of Serbia 6-2 6-7 6-2 in more than two hours of play.

The semi-finals were played in extremely poor air quality, with government data showing levels of PM2.5 particulates – small enough to deeply penetrate the lungs – nearly eight times the maximum recommended by the World Health Organisation in a 24-hour period.

The $US500,000 ($A682,000) WTA tournament has had a run of upsets, the most spectacular when Italian top seed and US Open winner Flavia Pennetta went out to a player ranked more than 400 places below her, Ukraine’s Lyudmyla Kichenok.