Elina Svitolina is through to the last 16 at the Berlin Open after Anna Kalinskaya withdrew partway through their opener on Tuesday.

Svitolina held a commanding 6-1 4-1 lead at the time before Kalinskaya was forced to pull out through injury after 43 minutes.

The Ukrainian had made a stellar start, winning the first three games before Kalinskaya got on the board with a love-hold.

Svitolina then won six straight games before the pair traded breaks, at which point Kalinskaya was unable to continue.

Madison Keys will also be joining Svitolina in the next round after a straight-sets win over Xinyu Wang.

After a tight first set, Keys found her rhythm in the second, triumphing 7-6 (7-3) 6-1, with the American looking particularly strong on serve, winning 83% of her first-serve points (30/36).

Keys will face Karolina Muchova in the next round, with the Czech overcoming Shuai Zheng 6-1 6-3 in just 59 minutes.

However, Clara Tauson has been knocked out of the tournament after Diane Parry prevailed in straight sets in an hour and a half.

The Frenchwoman came out on top 6-3 6-4 after saving all four break points she faced throughout.

Svitolina makes strong start on grass court

Svitolina enjoyed a strong finish to the clay-court swing, triumphing at the Italian Open before making it through to the French Open quarter-finals.

Now, with Wimbledon around the corner, she is looking to hit the ground running in the grass-court swing as she ups her preparation.

Granted, she was not on the court for long before Kalinskaya's unfortunate withdrawal, but she fired off four aces and converted five of the eight break points that she forced.

Keys and Muchova are in the same boat as they play their first grass-court tournament, with all players looking to adjust as quickly as they can before Wimbledon starts in just under two weeks.