Top 5 Photos, June 19: Pliskova twins clash; Venus wins in Birmingham

Grass-court play continued with two twin sisters clashing in their biggest meeting to date and a five-time Wimbledon champion beginning just her fourth Wimbledon tune-up tournament on Wednesday. These are the Top 5 photos that showcase the action.

1. World No. 3 Karolina Pliskova continued her grass-court campaign on Wednesday against twin sister Kristyna Pliskova at the Nature Valley Classic in Birmingham. It was their first WTA meeting and a match filled with nerves and tension as the two sisters battled. Left-handed Kristyna edged past Karolina in a close third-set tiebreaker, 6-2, 3-6, 7-6 (7), to claim the biggest victory of her career.

2. Juan Martin Del Potro made his first grass-court appearance at The Queen's Club since 2016. The third-seed ousted rising star Denis Shapovalov in his opening round, 7-5, 6-4, as he patiently waited for the right opportunities to finish points against the Canadian. Del Potro will face Feliciano Lopez in the second round, and will look to dismiss the Spaniard, just as he did at last year's Wimbledon.

3. Switching from clay to grass courts can sometimes be a tricky task. On Wednesday, French Open champion Ashleigh Barty faced a grass-court contender fresh off reaching the Nottingham final. The world No. 2 transitioned seamlessly to defeat Donna Vekic, 6-3, 6-4. and will face Jennifer Brady in her second-round match. The Australian defeated Brady at Indian Wells in straight sets earlier this year.

4. It's not typical to see Venus Williams play in a Wimbledon tune-up tournament, but on Wednesday, she advanced past Aliaksandra Sasnovich, 6-3, 6-4, in Birmingham. The five-time Wimbledon champion is attempting to capture her first grass-court title at a WTA event and 50th career crown. Williams will battle Qiang Wang for a spot in the quarterfinals.

5. World No. 1 Novak Djokovic signed autographs after an open training session in Belgrade at Janko Tisparevic's academy. The reigning Wimbledon champion will seek to lift his fifth trophy at the grass-court major.