What's happening here? Berdych wins two points on the trot to ease 30-0 ahead. The Czech in unchartered territory, never has he had such a handsome lead in this set.

Another faulty return from Djokovic, into the tramlines his forehand goes, and the Serb looks skywards and gives out a slight groan. The world number one has had little to grumble about in this set, though. It's a hold to 30 for Berdych, the Czech finding form but it's (probably) a little too late, for this set at least.

Andrew Castle
BBC tennis commentator on BBC Two

"Three first serves in a row from 15-30 make it 5-1. You can't attack him."

Image source, Getty Images

Oof! A splendid serve from Djokovic, full of spin and menace - Berdych unable to do anything other than direct it towards Boris Becker in the front row. Boris throws the ball back onto the court. I guess he doesn't need any tennis mementos.

A routine hold from the Serb, his first serve on song, as is the rest of his game to be honest.

Stephanie Siu:, external Such is the allure of the BBC live feed that I'm sitting in the O2 with my bro & he's reading the feed over watching the action!

An intake of breath from the spectators as they admiringly watch Djokovic on the run, turning defence into attack with a rasping crosscourt forehand winner.

A Berdych point! 17,000 spectators are whooping and whistling as the Czech produces an overhead at the net, eating into Djokoivc's lead. 15-30. Berdych then follows up with a snazzy ace to level at 30-30 and the Czech has some sort of momentum, pulling through to hold.

Image source, Getty Images

If Djokovic reaches the semi-final with a 3-0 record in the round-robin matches, he will be guaranteed to end the year as world number one regardless of what Federer does at this tournament and the Davis Cup final. It feels as if we're heading for a routine Djokovic victory because the Serb is eye-wateringly good - feather-soft touches at the net for a hold to love.

Robert Allen:, external I wonder if all these people busy writing Murray off, were the ones who said he'd never win one Grand Slam, let alone two!

Mark Farman:, external Andy needs to be more aggressive and punish his opponents, if his game matched his temperament he'd be number one in the world.

Carl Keegan:, external Well, three games in, that just about wraps it up for Berdych.

Andrew Castle
BBC tennis commentator on BBC Two

Image source, Getty Images

"Does Berdych has anything else in his game he can actually go to?"

Tim Henman
Former British number one on BBC Two

"Another relevant tactic against Djokovic is mixing up your speed of serve. The harder you serve, the harder it comes back!"

Berdych out of his comfort zone, dashing to the net, but his crosscourt volley drifts into the tramlines and Djokovic is ahead once again. From 15-30 to 15-40... two break points Djokovic... the crowd slow clap... Berdych shrugs his shoulders, looks towards his camp for answers...

Djokovic screws a return wide. One break point saved. Is there hope? Oh, deary me, the Czech is wide, wide, wide and Djokovic breaks once again.

Tim Henman
Former British number one on BBC Two

"It's obviously early days in this match, but Berdych has to know that this style of play doesn't work. Are we going to see him change anything? Come to the net occasionally? On the baseline, there's only going to be one winner."

At 30-0 Djokovic goes long and the crowd heartily applaud as Berdych wins his first point of the match. Hoorah! A double fault from Djokovic for 30-30, but for some reason it doesn't feel as if the Serb's dominance will be threatened. He launches a boomer of an ace to skip 40-30 ahead and the game ends with the familiar sight of Berdych failing to negotiate the barrier.

James Alex:, external I don't think Murray will win a Grand Slam again, Nishikori and Dimitrov coming up fast now. Someone like McEnroe, Wilander, Agassi, Sampras is what Murray needs, a proven Grand Slam champion.

Sue Barker
BBC tennis presenter on BBC Two

"We saw a masterclass from Roger Federer last night, but we could see another one from Novak Djokovic. He just seems to get better and better."

The story of this match begins with Djokovic nicking the opening point before proceeding to a 0-30 lead after coming out on top of a baseline tussle. Deep breaths from the Serb, who is quickly back in position and returning brilliantly.

The net must seem like a 10ft wall for Berdych as Djokovic collects three break points and breaks thanks to a stonking backhand return. Impressive stuff from the world number one.

Tim Henman
Former British number one on BBC Two

"With this being Berdych's last match of the year, you just want him to come out and see if he can make life uncomfortable for Djokovic."

Image source, BBC Sport

One victory - that's all Djokovic needs to ensure he end the year as the world number one. Should he achieve that feat he will join Pete Sampras, Roger Federer, Jimmy Connors, Ivan Lendl, John McEnroe and Rafael Nadal on the list of players who have finished year-end world number ones for three seasons.

Andrew Castle
BBC tennis commentator on BBC Two

"Has Murray got the right person in his corner with Amelie Mauresmo? That's not a criticism - but I think I would be feeling a bit vulnerable if I was her. I might be getting on the phone to Ivan [Lendl] and asking 'are you sure you're not free next year?'"

Image source, Getty Images

It's time to now focus on this afternoon's match because Djokovic and Berdych have strolled through the dry ice to a warm welcome and are currently warming up, while Tim Henman and Andrew Castle chat about Murray's future.

By the way, you can watch Sue and co by clicking the 'live coverage' tab on this page. There is also live coverage on BBC Radio 5 live sports extra.