(CNN) -- Novak Djokovic and Andy Murray were paired together in the same round robin group when the draw for the ATP World Tour Finals was made Saturday in London.
With the exception of early exits in this week's Paris Masters, the pair have dominated men's tennis in the latter part of the season and join Tomas Berdych of the Czech Republic and Frenchman Jo-Wilfried Tsonga in a tough Group A for the end of season finale.
Defending champion Roger Federer, who will officially lose his No.1 ranking to Djokovic Monday, heads Group B with fourth seed David Ferrer of Spain, Argentina's Juan Martin del Potro and Janko Tipsarevic of Serbia.
The top two from each group qualify for the semifinal knockout stage at the O2 Arena.
Murray, who followed up his Olympic gold medal in the singles with victory in the U.S. Open, where he beat Djokovic in an epic final, will play Berdych in his opener Monday.
"There's always pressure at all of the major tournaments you play but I feel a little bit more relaxed coming in this year than I have in previous years because I managed to win the U.S. Open," he told Press Association.
"But the only thing I can guarantee is that I'll give 110% on the court, fight as hard as I can until the end of all the matches and see where that gets me. Hopefully it'll get me a few wins."
Murray last met Djokovic in another gripping final at the Shanghai Masters where the Serbian came out on top to boost his chances of regaining the No.1 spot from Wimbledon champion Federer.
French Open champion Rafael Nadal is the only player in the top eight of the rankings to be absent in London, still recovering from his knee problems.
Meanwhile at the Paris Masters, unseeded Pole Jerzy Janowicz continued his extraordinary run as he beat Frenchman Gilles Simon 6-4 7-5 to reach the final.
The towering Janowicz beat Murray from match point down in the third round and once again showed his potential with a comfortable win over the home favorite at Bercy.
He will play Ferrer, who beat another Frenchman, Michael Llodra, 7-5 6-3 in the second semifinal.
Janowicz, 21, had to come through qualifying to take part in the Masters 1000 tournament and will be playing his seventh match in the French capital Sunday.
In the women's Fed Cup final Saturday, Petra Kvitova gave holders Czech Republic a 2-0 lead when she beat Serbia's Jelena Jankovic 6-4 6-1 in the second singles.
Kvitova is still recovering from the virus which forced her out of last week's WTA Championship but needed only an hour and 20 minutes to see off Jankovic.
In the first rubber of the final, Lucie Safarova beat former World No.1 Ana Ivanovic 6-4 6-3.
Sunday will see a doubles match and the reverse singles in Prague.