Heather Watson was under pressure as she faced a break point but a good serve and then a fine volley allowed her to see off the danger and hold for 6-5.
Shouts of "come on, Heather" as Tamara Korpatsch serves to force a first-set tie-break.
Post update
Andrew Cotter
Tennis commentator on BBC TV
Duckworth is showing variety and being entertaining. He's keeping Murray honest in this fourth set. It's still anyone's.
Post update
*Murray 4-6 6-3 6-2 3-4 Duckworth
No-one is giving an inch in this fourth set with Duckworth giving it his all as the Australian again holds serve.
Post update
Jonathan Jurejko
BBC Sport at Wimbledon
Feels like the atmosphere is a little more boisterous since the restart...
I presume those who didn't have a ticket at the start have filtered in.
One person shouts "I love you Andy!" as Murray is about to serve, bringing a classic side-eye from the Scot and no hint of a smile.
This is business, not pleasure.
Post update
Murray 4-6 6-3 6-2 3-3 Duckworth*
Aces aplenty for Murray as he holds on serve. Whether it is because the roof is closed and the sound is more contained or the spectators are just getting into things more, the atmosphere has moved up a level now with cheers and whoops with every point.
Post update
Watson 5-4 Korpatsch*
Alan Jewell
BBC Sport at Wimbledon
Heather Watson just served for the first set against Tamara Korpatsch but the German broke back courtesy of a superb forehead return and an errant Watson backhand.
BBC SportCopyright: BBC Sport
Post update
*Murray 4-6 6-3 6-2 2-3 Duckworth
Some good shots from both players, Duckworth hitting a backhand volley at the net and Murray catching his opponent out with a backhand slice but Duckworth serves well to hold to 30.
Post update
Murray 4-6 6-3 6-2 2-2 Duckworth*
Good serving once again from Murray as an 11th and 12th ace of the match ensures he holds comfortably.
Post update
*Murray 4-6 6-3 6-2 1-2 Duckworth
There's a good mix to Duckworth's shots again, the highlight of which is a backhand winner that is angled out of Murray's reach.
Duckworth then serves well to close out the game. An important hold.
Post update
Murray 4-6 6-3 6-2 1-1 Duckworth*
That pause in play doesn't seem to have affected Murray's play and he wins on serve, caressing the ball over the net beautifully to move onto 40-15 before slamming down an ace to take the game.
Getty ImagesCopyright: Getty Images
Get Involved
#bbctennis
Matt McGlone: There's something about watching Andy Murray under the roof at Wimbledon. Trying to cherish it, who knows how many more times we'll see it!
Watson breaks
*Watson 4-2 Korpatsch
Alan Jewell
BBC Sport at Wimbledon
After a quiet start, the Court One crowd is finding its voice with plenty of cheers as Heather Watson gets the first break of the match against Tamara Korpatsch.
Watson found the baseline on successive points to make the breakthrough.
Post update
John McEnroe
Three-time Wimbledon singles champion on BBC TV
That gave Duckworth time to regroup. He needed that and is looking to benefit from it. Murray has got to keep in attack mode.
Post update
*Murray 4-6 6-3 6-2 0-1 Duckworth
"Let's go Murray, let's go" echoes around a now enclosed Centre Court, the fans very much enjoying the new acoustics as Murray takes his first point to make it 15-15.
Duckworth is serving well, though, and takes the first game of this set. Just the start he needed.
Post update
Murray 4-6 6-3 6-2 0-0 Duckworth*
Will that halt Murray's momentum? Or has it just delayed his victory?
We're under way in this fourth set.
Post update
Jonathan Jurejko
BBC Sport at Wimbledon
BBC SportCopyright: BBC Sport
Of course there was a whoop when someone finally pressed the light switch.
Another quick warm-up for the players and then we go again.
Sinner beats Wawrinka
Sinner 7-5 4-6 6-3 6-2 Wawrinka
Men's 10th seed Jannik Sinner finally quashes Stan Wawrinka's challenge.
Three-time Grand Slam winner Wawrinka threatened when he won the second set, but Italian Sinner wraps things up as he takes the fourth and final set 6-2.
Post update
The roof closes and the lights flick on, prompting a cheer from the fans.
Murray and Duckworth hit the ball to each other to warm up. Play gets back under way in two minutes.
Post update
Jonathan Jurejko
BBC Sport at Wimbledon
BBC SportCopyright: BBC Sport
Feels like the moment at a gig before the main band are about to come on.
Excited chatter and an energy building for the entertainment that's going to come.
Probably a queue for a beer in a plastic cup, too.
Got to be a cheer coming when the lights flash on and illuminate the stage.
Post update
*Watson 2-2 Korpatsch
Alan Jewell
BBC Sport at Wimbledon
Four service holds to start on Court One between Heather Watson and Tamara Korpatsch.
Billie Jean King captain Anne Keothavong is among the crowd watching on under the roof.
Live Reporting
Gary Rose, Amy Lofthouse and Becky Grey
All times stated are UK
Post update
Watson 6-5 Korpatsch*
Alan Jewell
BBC Sport at Wimbledon
Heather Watson was under pressure as she faced a break point but a good serve and then a fine volley allowed her to see off the danger and hold for 6-5.
Shouts of "come on, Heather" as Tamara Korpatsch serves to force a first-set tie-break.
Post update
Andrew Cotter
Tennis commentator on BBC TV
Duckworth is showing variety and being entertaining. He's keeping Murray honest in this fourth set. It's still anyone's.
Post update
*Murray 4-6 6-3 6-2 3-4 Duckworth
No-one is giving an inch in this fourth set with Duckworth giving it his all as the Australian again holds serve.
Post update
Jonathan Jurejko
BBC Sport at Wimbledon
Feels like the atmosphere is a little more boisterous since the restart...
I presume those who didn't have a ticket at the start have filtered in.
One person shouts "I love you Andy!" as Murray is about to serve, bringing a classic side-eye from the Scot and no hint of a smile.
This is business, not pleasure.
Post update
Murray 4-6 6-3 6-2 3-3 Duckworth*
Aces aplenty for Murray as he holds on serve. Whether it is because the roof is closed and the sound is more contained or the spectators are just getting into things more, the atmosphere has moved up a level now with cheers and whoops with every point.
Post update
Watson 5-4 Korpatsch*
Alan Jewell
BBC Sport at Wimbledon
Heather Watson just served for the first set against Tamara Korpatsch but the German broke back courtesy of a superb forehead return and an errant Watson backhand.
Post update
*Murray 4-6 6-3 6-2 2-3 Duckworth
Some good shots from both players, Duckworth hitting a backhand volley at the net and Murray catching his opponent out with a backhand slice but Duckworth serves well to hold to 30.
Post update
Murray 4-6 6-3 6-2 2-2 Duckworth*
Good serving once again from Murray as an 11th and 12th ace of the match ensures he holds comfortably.
Post update
*Murray 4-6 6-3 6-2 1-2 Duckworth
There's a good mix to Duckworth's shots again, the highlight of which is a backhand winner that is angled out of Murray's reach.
Duckworth then serves well to close out the game. An important hold.
Post update
Murray 4-6 6-3 6-2 1-1 Duckworth*
That pause in play doesn't seem to have affected Murray's play and he wins on serve, caressing the ball over the net beautifully to move onto 40-15 before slamming down an ace to take the game.
Get Involved
#bbctennis
Matt McGlone: There's something about watching Andy Murray under the roof at Wimbledon. Trying to cherish it, who knows how many more times we'll see it!
Watson breaks
*Watson 4-2 Korpatsch
Alan Jewell
BBC Sport at Wimbledon
After a quiet start, the Court One crowd is finding its voice with plenty of cheers as Heather Watson gets the first break of the match against Tamara Korpatsch.
Watson found the baseline on successive points to make the breakthrough.
Post update
John McEnroe
Three-time Wimbledon singles champion on BBC TV
That gave Duckworth time to regroup. He needed that and is looking to benefit from it. Murray has got to keep in attack mode.
Post update
*Murray 4-6 6-3 6-2 0-1 Duckworth
"Let's go Murray, let's go" echoes around a now enclosed Centre Court, the fans very much enjoying the new acoustics as Murray takes his first point to make it 15-15.
Duckworth is serving well, though, and takes the first game of this set. Just the start he needed.
Post update
Murray 4-6 6-3 6-2 0-0 Duckworth*
Will that halt Murray's momentum? Or has it just delayed his victory?
We're under way in this fourth set.
Post update
Jonathan Jurejko
BBC Sport at Wimbledon
Of course there was a whoop when someone finally pressed the light switch.
Another quick warm-up for the players and then we go again.
Sinner beats Wawrinka
Sinner 7-5 4-6 6-3 6-2 Wawrinka
Men's 10th seed Jannik Sinner finally quashes Stan Wawrinka's challenge.
Three-time Grand Slam winner Wawrinka threatened when he won the second set, but Italian Sinner wraps things up as he takes the fourth and final set 6-2.
Post update
The roof closes and the lights flick on, prompting a cheer from the fans.
Murray and Duckworth hit the ball to each other to warm up. Play gets back under way in two minutes.
Post update
Jonathan Jurejko
BBC Sport at Wimbledon
Feels like the moment at a gig before the main band are about to come on.
Excited chatter and an energy building for the entertainment that's going to come.
Probably a queue for a beer in a plastic cup, too.
Got to be a cheer coming when the lights flash on and illuminate the stage.
Post update
*Watson 2-2 Korpatsch
Alan Jewell
BBC Sport at Wimbledon
Four service holds to start on Court One between Heather Watson and Tamara Korpatsch.
Billie Jean King captain Anne Keothavong is among the crowd watching on under the roof.