Hello and welcome to our LIVE coverage of the ATP World Tour Finals Group B clash between Juan Martin Del Potro and Janko Tipsarevic, starting no earlier than 7.45pm and - thanks to the doubles match between the Byran Bros and Qureshi-Roger finishing on time - it should be before 8pm.

Thanks for joining me, Reda Maher, today. I'll be back tomorrow with more action from the O2 as Andy Murray and Novak Djokovic face Jo-Wilfried Tsonga and Tomas Berdych respectively. That should be an excellent day's tennis, and you'd hope less one-sided than today's. If you want to chat about those matches, or the ones just past, feel free to Tweet me @Reda_Maher. See you tomorrow at around 2pm UK time!

DEL POTRO 6-0 6-4 - GAME SET AND MATCH! Fantastic athletic point as Tipsy somehow musters up the running to flick it away from the big man. But he reacts with fury as an unforced error on the forehand levels at 15. And two match points now as DelPo turns it on, with the Argentine taking them at the first time of asking as Tipsy returns his second serve beyond the baseline. One hour and 16 minutes and DelPo triumphs.

@keeper9: "The Dreaded Bagel. Sounds like the Justice League nemesis they came up with at 2am, starving hungry and sleep deprived. "; @JeanThornton4: "He must really be ill. " - Yes, he is. In my opinion he should have pulled out and let someone else in, but he's not the sort to give up.

DEL POTRO 6-0 5-4 - A very solid hold from the improving Tipsarevic but it's come too late, Del Potro serving for a straight-sets win now.

DEL POTRO 6-0 5-3 - The problem for Tipsy now is that DelPo just has too much power for him, the Argentine holding to 15. The Serb serving to stay in the match.

DEL POTRO 6-0 4-3 - Tipsy is having to fight for every point now. He manages to hold off deuce thanks to a spectacular point at the net as he makes some impossible volleys under real pressure. Nice one.

DEL POTRO 6-0 4-2 - Say what you like about his performance here in London - Tipsy is not close to 100% but it has been his dream to play at this level - but he has a lot of fight, battling gamely for every point now. But he backhands wide after a thrilling rally, and forehand to net off his next return, as DelPo defends the break.

DEL POTRO 6-0 3-2 - BREAK! Del Potro has a break point now as he works a tired-looking Tipsy on some long rallies, another of which sees the Serb double-hand it long and that could well be the match.

DEL POTRO 6-0 2-2 - Despite that confidence boosting love hold, Tipsy is still getting little joy on DelPo's serve. Comfortable hold.

DEL POTRO 6-0 1-2 - Much much better from Tipsarevic, who finally gets his service game in check as he holds to love, no chance for DelPo there really.

DEL POTRO 6-0 1-1 - Boosted by getting on the board, Tipsy goes on the offensive to volley cleanly for 15-15 but Del Potro blasts some big deliveries in to hold from there.

DEL POTRO 6-0 0-1 - A great serve from the Serb gives him advantage again but he double faults back to deuce. Make it stop. Ah a good delivery this time for advantage, and FINALLY he holds as DelPo ends a baseline rally with a low backhand to net.

DEL POTRO 6-0 0-0 - It's not getting any better for Tipsy, who is arguing with everyone including himself as he falls 0-30 at the start of what will surely be the last set. He does pull one back as a DelPo mis-hit allows the smash... But a trade of blows gives DelPo another break point, which he fails to take as a weak forehand return nets. Now Tipsarevic has advantage but DelPo dictates a baseline rally and the Serb nets a forehand. Deuce.

Tipsarevic falls to the dreaded bagel after only getting 43% first serves in and winning a rotten 15% of his second-serve points. Howler.

DEL POTRO 6-0 - SET! THE DREADED BAGEL! Del Potro serving for the bagel first set and, after dropping the first point, his sliced backhands eventually see Tipsarevic net. Then a monster serve catches Tipsy off balance, and a very turny forehand moves so much that Tipsy can't get across in time to make decent contact, weakly backhanding low. Two set points which he takes with an ACE down the middle. Too easy.

DEL POTRO 5-0 - BREAK! Tipsarevic faces another break point though as he stumbles into a backhand that hits the deck, but it's saved as DelPo flings one wide. He challenges but it looked wide to me, yes says HawkEye. Deuce. But another break point as Tipsy falls foul of the net, but DelPo weakly backhands to net for deuce again. Riddled with errors this. Another break point now as Tipsy staggers into a backhand to net, and he takes this one as Tipsy goes wide after a baseline exchange. Bagel?

DEL POTRO 4-0 - Tipsarevic falls three break points down as a crushing DelPo forehand kisses the line, the scrambling Serb only able to fling his response off court. Good save on the first one as Tipsy meets a trademark DelPo forehand screamer with one of his own, and the second is pulled back as DelPo weakly nets. Then a fantastic diagonal forehand deceives DelPo to strike the line, and we are on deuce.

DEL POTRO 4-0 - Tipsarevic should have had a winner there but spins a diagonal forehand well wide. Again he should pull one back but overhits a backhand volley with DelPo stranded and, as the Argentine's mate Sergio Aguero watches on, DelPo holds to love.

Is Tipsarevic out of his depth here, or do you think he's genuinely suffering from his cold? I just don't see what weapons he has to compete with the top eight (seven excluding Nadal), for me he's totally topped out at world no.9. Let me know what you think on Twitter @Reda_Eurosport.

DEL POTRO 3-0 - BREAK! DelPo could break again here as Tipsy strikes long to fall 0-30. Fine serve down the middle though, DelPo able to spin on to his backhand but striking it to the ground. A sudden change of pace on his backhand sees Tipsarevic level, DelPo left stumbling into that, but DelPo brings up break point as his wideish forehand catches Tipsy on the run, the Serb netting his response! And DelPo takes it with a fantastic dipping forehand of immense power that kisses the line!