Wimbledon day two - use the 'watch & listen' tab for live BBC coverage (UK only)
LIVE: Serena Williams, 44, makes Wimbledon return v 20-year-old Australian Maya Joint under Centre Court roof
LIVE: Stan Wawrinka 7-6 (9-7) Matteo Berrettini on Court One, GB's Jan Choinski two sets up on court 16
French Open champion Alexander Zverev overcomes Alexander Blockx 6-4 6-7 (8-10) 7-6 (7-5) 7-6 (7-0)
Defending women's champion Iga Swiatek and Elena Rybakina win but men's fourth seed Ben Shelton beaten by qualifier
GB's Katie Swan, Arthur Fery and Jacob Fearnley through to second round, Toby Samuel goes close v 15th seed Jakub Mensik
Experience Wimbledon with SIGNALS - a live trial combining real-time data, fan interaction and insight from Centre Court
*Blockx 4-6 7-6 (10-8) 6-6 (3-2) Zverev
As expected, Alexander Blockx and second seed Alexander Zverev are into a third-set tie-break on Centre Court.
Blockx won the breaker at the end of the second set to level the match.
A double fault from Zverev gives Blockx a narrow advantage at 3-2 up with a mini-break.
Mensik 5-7 6-3 6-3 3-6 7-6 (10-7) Samuel
It's all over as Toby Samuel can't get Jakub Mensik's first serve into play.
A magnificent effort from Britain's Samuel, but Mensik's class showed in the end.
The crowd show their appreciation to Samuel with chants of "Toby Toby" as the players walk off court.
Image source, Getty Images*Mensik 5-7 6-3 6-3 3-6 6-6 (9-6) Samuel
Jakub Mensik is serving well now as Toby Samuel fails to get another one into play before the Czech 15th seed outplays the Briton in a rally.
A double fault at the worst possible time from Samuel then offers three match points for Mensik.
*Mensik 5-7 6-3 6-3 3-6 6-6 (6-6) Samuel*
Jakub Mensik brings out a perfect drop shot at just the right time as Toby Samuel scrambles forward with no reward.
That will be hard on the legs at this point in the match for Samuel.
Mensik then draws level with a big first serve before another change of ends in this 10-point tie-break.
Image source, PA MediaSvitolina 5-7 2-3 Snigur*
Elina Svitolina led 40-15 in her latest service game but Daria Snigur has roared back with a huge break of serve. That's the fifth time she's broken the eighth seed in the match.
Image source, Getty Images*Mensik 5-7 6-3 6-3 3-6 6-6 (3-5) Samuel*
Jakub Mensik is showing a bit of frustration as he skews a shot wide to give Toby Samuel the edge.
The Briton can't take advantage as a forehand sails long, but Mensik then goes wide with backhand after a long rally.
Samuel keeping his nose in front at the moment.
Image source, Getty ImagesMensik 5-7 6-3 6-3 3-6 6-6 (2-2) Samuel*
An early mini break for Toby Samuel as Jakub Mensik hits tiredly into the net following a rally, but the Czech 15th seed fights back.
Samuel then plants a forehand long, but gets some luck on the next point via the net.
You can't separate these two at the moment.
*Svitolina 5-7 2-2 Snigur
On court two, eighth seed Elina Svitolina has lost the opening set to Daria Snigur.
Svitolina led 4-0 after breaking in each of Snigur's first two service games but then lost four consecutive service games of her own as the world number 77 took the set 7-5.
The second set is going with serve.
Image source, Getty Images*Blockx 4-6 7-6 (10-8) 4-5 Zverev
The two Alexanders continue to serve well and snuff out any chances of breaks.
There's been just the one so far, when Zverev broke towards the end of the first set on his way to winning it.
We're getting closer to a third-set tie-break on Centre.
At the moment, though, there's definitely more drama on court three in the match involving Toby Samuel...
Image source, Getty Images*Mensik 5-7 6-3 6-3 3-6 6-6 (0-0) Samuel
Jakub Mensik's backhand at the net just drops on the line and Toby Samuel finds himself in bother at 15-30.
Mensik then crashes a forehand wide when he looked well placed to bring up two match points.
This is tense now, but Samuel comes through to hold with a couple of good first serves.
Tie-break time.
Mensik 5-7 6-3 6-3 3-6 6-5 Samuel*
Harry Poole
BBC Sport at Wimbledon
Whatever ultimately happens here, this has been a sensational effort from Toby Samuel.
The Briton was ranked outside of the top 1,000 men's players just 12 months ago, but here he is going toe-to-toe with the world number 18 into the fourth hour of a thrilling encounter in only his second Grand Slam main draw match.
He has the crowd on their feet as he digs deep to break Jakub Mensik as the Czech served for the match and looks like he has plenty more still to give here.
Samuel claimed the biggest win of his career by ousting 45th-ranked Argentine Juan Manuel Cerundolo on route to the Eastbourne semi-finals last week, but he's potentially only a couple of games away from completely outdoing that victory.
Image source, Getty ImagesMensik 5-7 6-3 6-3 3-6 6-5 Samuel*
Jakub Mensik works Toby Samuel around the court to reach game point as the Briton charges from left to right with no reward.
Mensik seals it with an ace and now Toby Samuel will have to serve to stay in the match.
*Mensik 5-7 6-3 6-3 3-6 5-5 Samuel
Dom Inglot
Former British tennis player on BBC TV
We've said that Mensik has the big serve that can bail him out of trouble, but all of his serves there were 117mph, 118mph. It's almost as if he decided to take the pace off completely.
Only a couple games ago he was serving 130mph, 135mph. It's different now.
*Mensik 5-7 6-3 6-3 3-6 5-5 Samuel
Every point from Toby Samuel is being met with loud cheers on court three. The crowd are trying to will the Briton to victory.
An inch-perfect drop shot at the net is met with an even louder cheer before Samuel seals the hold with a backhand across court.
Which way is this one going?
Mensik 5-7 6-3 6-3 3-6 5-4 Samuel*
Now then, with some luck from the net and some wayward shots from Jakub Mensik, Toby Samuel all of a sudden has three chances to break straight back.
The Briton then does it at the first attempt as Mensik plants a shot into the net.
Great scenes on court three.
Blockx 4-6 7-6 (10-8) 2-2 Zverev*
A game lasting about seven minutes - a marathon in the context of this match - ends with Alexander Blockx holding serve.
He had to recover from 15-40 down to do so, though.
*Mensik 5-7 6-3 6-3 3-6 5-3 Samuel
Break point for Jakub Mensik as Toby Samuel goes into the net but the Briton saves it by getting the better of a short rally.
Samuel then undoes his good work by double faulting before planting a forehand long.
Mensik, after being a break down earlier in the fifth set, will now serve for the match.
Mensik 5-7 6-3 6-3 3-6 4-3 Samuel*
Uh oh, trouble for Toby Samuel as he falls to 0-30 against Jakub Mensik.
Samuel fights back by coming into the net to put away a volley, before Mensik hammers a forehand return long.
Samuel sends down and ace but the game does to deuce as he skews a forehand long.
Click 'Get Involved' to have your say
If there's one match I'd love to have been there to watch it's Wawrinka v Berrettini - two great players, Stan retiring and Matteo's glittering start to his career blighted by injuries. Lovely guys to watch, it's not just the Brits we go to cheer.
JE
Wawrinka 2-1 Berrettini*
Three-time major champion Stan Wawrinka is appearing in his final Wimbledon before his planned retirement later this year.
The 41-year-old Swiss player is up against Italian Matteo Berrettini on Court One.
Berrettini is a former Wimbledon runner-up and was looking like he had rediscovered some excellent form at the recent French Open, when injury once again halted his progress.
Image source, Getty ImagesBBC One: Day 2, Evening. BBC Sport.
Watch here at 20:30
