TIANJIN, China — Top-seeded Karolina Pliskova needed six match points to beat Varvara Lepchenko 6-2, 6-7 (3), 6-3 and advance to the second round of the Tianjin Open on Monday.
Pliskova will next face Polona Hercog, who defeated Lara Arruabarrena 7-6 (5), 6-2.
Also, Russian qualifier Veronika Kudermetova beat 2014 champion Alison Riske 5-7, 6-1, 7-5, fifth-seeded Hsieh Su-Wei beat Ajla Tomljanovic 7-6 (4), 7-5, and Magda Linette defeated Evgeniya Rodina 2-6, 6-1, 6-4.
MASON, Ohio — Juan Martin del Potro advanced to the second round of the Western & Southern Open with a 3-6, 7-6 (1), 6-0 upset of 10th-seeded Tomas Berdych on Tuesday.
The 30th-ranked del Potro shook off a first-set loss, jumping out to a 4-1 lead in the second set before settling for a win in the tiebreak, which he led 5-0 and clinched with an ace. He built on his momentum by rolling through the third set against the Wimbledon semifinalist, improving to 12-0 in first-round matches this season.
Berdych was playing his first match since withdrawing from last week’s Rogers Cup in Montreal with a rib injury.
Ninth-seeded David Goffin became the first seeded man to be knocked out in Cincinnati, falling to Nick Kyrgios, 6-2, 6-3 in a first-round match. Kyrgios will meet qualifier Alexandr Dolgopolov in the second round after Dolgopolov defeated Kevin Anderson 6-4, 7-6 (6).
In women’s first-round action, Karen Khachanov beat Diego Schwartzman 6-1, 1-6, 6-3, and Ashleigh Barty beat Varvara Lepchenko, 6-4, 6-4 in a matchup of two qualifiers.
LONDON — American Varvara Lepchenko tested positive four times for meldonium, according to the International Tennis Federation, which cleared her because it was determined she took the substance before its ban went into effect on Jan. 1.
The ITF announced Tuesday that Lepchenko had been provisionally suspended in March but it was later determined that she “bore no fault or negligence for the violation.”
Meldonium, also known as mildronate, is the same substance for which Maria Sharapova tested positive, drawing a two-year ban that she has appealed. She acknowledged taking the drug in January.
The Latvian-made drug is typically used for heart conditions.
The ITF said meldonium was in Lepchenko’s system in decreasing amounts on Jan. 7, Feb. 1, March 1 and April 7. She appealed her provisional suspension, saying she had last taken mildronate tablets “on or around” Dec. 20.
The 30-year-old Lepchenko, who was born in Uzbekistan, is No. 79 in this week’s WTA rankings.