This was yet another great contest between the two longtime rivals who don't ever seem to give fans anything else.
In the other singles match, Tomas Berdych beat Jo-Wilfried Tsonga in three sets, which kept the advancement picture cloudy.
Djokovic and Berdych will meet on Friday. If Djokovic wins, he is in the semifinals. If he loses, the picture is far less clear.
Check out the scores and recap of all the day's action from the O2 below.
Wednesday's Singles Results
(1) Novak Djokovic defeats (3) Andy Murray; 4-6, 6-3, 7-5
(5) Tomas Berdych defeats (7) Jo-Wilfried Tsonga; 7-5, 3-6, 6-1
Wednesday's Doubles Results
(5) M. Bhupathi/R Bopanna defeats (4) R Lindstedt/H Tecau; 6-3, 5-7, 10-5
(8) J Marray/F Nielsen defeats (2) M Mirnyi/D Nestor; 7-6 (3), 4-6, 12-10
Djoker Edges Out Another Thriller
This is without a doubt the best rivalry going in tennis. These two deliver every time they meet each other and this one was no different.
It didn't look like it would be that way at the start. Murray broke Djokovic in the match's first game, and he was drilling his serve. In fact, he lost only three points on his serve the entire first set. That is nearly impossible to do against the elite return of Djokovic, but Murray was rolling.
It's not like anyone expected Djokovic to roll over after losing a set, though, and he battled back to a convincing win in the second.
The third set was even and they stood tied at five games apiece. Djoker broke Murray, and Murray was about to return the favor as he had two break points in the next game, but Djoker would not allow that to happen.
He crushed a forehand winner and then a service winner, and Murray made a couple of errors in deuce. Game. Set. Match.
Berdych Dominates Third
Tomas Berdych and Jo-Wilfried Tsonga traded sets early. The powerful Berdych was dominating on his serves, but he was having a hard time getting breaks.
Then the third set rolled around. Berdych quickly picked up a break and it seemed to destroy Tsonga's will. He was not the same player, and Berdych punished him.
By the end of this match, Tsonga looked flat out disinterested.