To wrap up on Centre Court on Tuesday, it's Aliaksandra Sasnovich against Serena Williams.

A slightly shell-shocked Sasnovich thanks everyone for their support, and says how sad she is for Serena and wishes her all the best.

She puts on her mask, waves to the crowd, and leaves the court with some assistance.

The chair umpire comes down to see if she's OK - she isn't. She's sobbing.

Serena falls to the ground mid-rally.

Serena looks as if she is about to cry.

SASNOVICH 3-3 WILLIAMS: Williams is back on court but not moving very happily. Let's see if she can serve. Coming an hour after poor Adrian Mannarino had to retire from his match, it's not good scenes.

Serena goes off court for a medical time-out.

Looks like she slipped and jarred her front foot or something.

SASNOVICH 2-3 WILLIAMS: Serena has landed badly on a heavily strapped right leg.

SASNOVICH 1-3 WILLIAMS: Fourth time is the charm. Sasnovich isn't hitting too badly but Williams is returning with sizzle.

SASNOVICH 1-2 WILLIAMS: There's all sorts of chaos in the stands on Centre Court at the moment - are people going to get their trains? When Serena Williams is on court?

SASNOVICH 1-1 WILLIAMS: First ace of the match goes to the Belarusian, which would have got you pretty good odds.

SASNOVICH 0-1 WILLIAMS: Serena Williams has never lost in the first round at Wimbledon. She starts off well with a hold.

Another great champion takes to the court - and she's in search of Grand Slam number 24.