Good afternoon everyone, and welcome to LIVE updates from the first of today's two semi-finals from Doha. First up Roger Federer, seeded two, faces third seed Jo-Wilfried Tsonga.

GAME, SET AND MATCH FEDERER! Federer opens up a 4-2 lead as two second serves and two missed returns prove so costly to Tsonga. Another ace from Federer, and he leads 5-2. Tsonga whips a forehand out of the court and Federer brings up four match points. He only needs the one as he completes the victory with a stunning smash at the net. Will be some match if he faces Rafael Nadal in the final. Tsonga made 28 unforced errors, 17 from Federer.

A third love service game from Federer in succession. 14 points has now gone to the Swiss player on his serve without reply. We are into the tie-break.

A sublime drop shot from Tsonga in that game. Brings Federer to the net before he converts a winning volley. Leads 40-30, but a forehand flies long moments later. Federer then knocks a backhand long on advantage to Tsonga to allow Federer to pocket the game. Another game, another without a break. Federer serving to force the tie-break.

Another love service game from Federer. He has now won ten straight points on his serve. Looking unbreakable on serve at the moment. Tsonga really has to hold in this next game otherwise it could be curtains for him.

Tsonga continues to ask the question of Federer. Fairly finding some venom on his serve. Federer reading the Tsonga serve, but the power of the Frenchman is proving problematic. Federer serves to stay in the set.

A love game from Federer. Just what he needed to stifle the Tsonga charge. The Frenchman gives away too many cheap points, and Federer remains unbroken in the set. Just the one break of serve so far in the match.

Tsonga continues to bludgeon some forehands and backhands around the court with some relish. The Frenchman not lacking aggression, but continues to seek out a break. He holds in that game as Federer serves to level.

Tsonga and Federer reached deuce on the world number two's serve, but he gives away a cheap point as he knocks a groundstroke long from the back of the court. Federer is quick to pick up the next point to extinguish the threat of a break. Tsonga certainly looking more lively than in the first set.

Tsonga unleasing some enormous power on his forehands. Really drilling through the ball with some venom. Federer fights back to deuce aided by one explosive backhand winner up the line before Tsonga hits the tape with a volley at the net. Tsonga being forced to battle, but he comes up with a couple of timely winners. He leads 3-2. Games on serve.

Another half-chance for Tsonga in that game. Managed a couple of points on his opponent's serve, but not quite enough to get himself over the line. Both men missing opportunities to apply some pressure in this set. We remain on serve.

Tsonga saves a break point as he catches Federer off guard by coming to the net to convert a smash. A big point from the Frenchman. The game goes to a couple of deuces, but Tsonga does enough to stave off the constant threat of a Federer break. He leads by the odd game in three.

Some lovely movement from Federer. Really getting through his forehands with some ferocity. Turning through the ball with classic ease. Tsonga comes up with a couple of points, but Federer completes the job with a big first serve and a winning volley. We remain on serve.

A strong start to the second set from Tsonga as he holds in the opening game of the second set. Really has to impress himself upon the great man soon if he is going to extend this match longer than two sets.

SET! A shout of anguish from Tsonga as Federer forces him to drop a backhand into the net. In no time at all the Swiss has three set points, and with another excellent second serve, he clinches it at the first attempt.

Another venemous Tsonga forehand, but it's just too long - 15-all. The Frenchman pulls out something special next, though - a lob on the backhand which leaves the advancing Federer stranded. Spurred on, Tsonga holds to thirty.

Tsonga hits a beautiful passing shot on the run to take the first point -but that's as good as it gets for the third seed - Federer powers his way back into the game with four clinical points and is now just one game away from the first set.

That's an excellent service game from Tsonga - he has plenty of power behind the forehand and hits a couple of booming efforts, and closes out to fifteen with an assured overhead volley.

Federer slips to a 15-30 deficit on his serve, but sends down an ace to the middle to get back on terms. He wins the next point trading backhands with Tsonga, and wins the game after keeping his opponent on the back foot after a kicking second serve.

Tsonga on the board - and a much better showing from the Frenchman, who holds to fifteen. Much more power and conviction in his serve, and that made his groundstrokes easier to execute.

Hold to love from Federer, who even in these early stages seems to have the ball on a string. A very confident opening, and Tsonga will have to raise his game quickly.