Sloane Stephens won her first match of 2020 after prevailing at the WTA Monterrey Open, while Venus Williams' woes continued.

Stephens – the American fifth seed – ended her drought by outlasting Emma Navarro 6-4 5-7 6-1 in Monterrey on Monday.

Prior to this week, Stephens had featured in four tournaments without a win, including a first-round exit at the Australian Open.

But the 2017 US Open champion finally opened her account for the year via the WTA International event after two hours, 17 minutes.

Former world number one Williams and her winless year continued, however, following a 4-6 6-3 6-2 defeat to qualifier Anna Karolina Schmiedlova.

Seven-time grand slam winner Williams battled but the 39-year-old was eventually eliminated after two hours, 29 minutes on court.

Elsewhere, Wang Yafan, Rebecca Peterson, Olga Govortsova, Astra Sharma and Marie Bouzkova progressed to the second round.