3-5 - Federer breaks serve! Haas gets a very unfortunate line call which disrupts his rhythm at 15-15, and the German appears pretty rattled, firing a forehand into the net to give Federer two break points. A good serve saves the first, and the Swiss hits long to squander the second. A third break point is rescued with a serve down the T, and a fourth in an almost identical fashion, but a fifth is put into the net by the German.

3-3 - Haas storms to 40-0 with a stunning half-volley pick up to give him a convincing advantage, and the German holds to 15 to remain on terms with Federer in this third set.

2-2 - Haas completes another commendable service hold with a sliced serve out to Federer's backhand forcing the error, after he had once again been pushed out to 40-30.

1-1 - Haas matches his opponent's dominance in holding to love, and the German regains his rhythm, but he will still be rueing how he lost his composure at the crucial moment in the previous set.

5-7 - Federer clinches the second set! Haas plays a stunning backhand winner down the line to take the game to 15-15, but an over-sliced forehand, followed by an overhit pass give Federer a second set point. The Swiss sends a forehand into the net after stretching to reach a fierce forehand from Haas. Another sublime winner from Federer gives him a third set point, and this time Haas hits long.

5-5 - Haas moves swiftly to 30-15 with two big first serves, but the German throws in a double fault to give Federer a sniff of an opportunity. A fine backhand pass forces Haas to plant a backhand into the net, but the German saves the break point with a huge first serve. Haas holds his nerve and levels once more, showing great character on serve.

4-4 - Haas looks comfortable at 30-15, but attempts an audacious flick behind the legs which goes straight into the net: that was sloppy from the German. The 24th seed responds with a good first serve down the centre of the court to level at 4-4.

3-3 - Federer misses a very tricky forehand and, such are the expectations on him, it prompts a groan from the crowd. Haas moves to 40-30 with a clinical serve and volley, and the German levels at 3-3.

2-2 - Haas plays a delightful half-volley at the net to close out his second service hold of the set after Federer had pushed him to 40-30. The German is hanging on well.

1-1 - Haas races to 40-0 with ease, finding a good rhythm and not erring from it. The German goes wide with an attempted forehand pass cross court, but he closes out the game with a crisp backhand volley.

0-1 - Federer begins the second set with a comfortable service hold to love, finding three first deliveries and testing Haas with every shot. The German must raise his level now.

TB3-5 - Haas somehow reaches a forehand with a big lunge, whipping the ball down the line, but the Swiss responds with a stunning backhand return to lead 5-3.

TB1-2 - The first three points of the tie-break go with serve as Federer finds the line on two occasions after Haas had found a big delivery to open proceedings.

6-5 - A huge smash from Haas after scampering backwards gives him 30-15, but a poor drop shot is seized upon by Federer who piles the pressure on his opponent. Haas holds with impressive composure, and puts the onus back on Federer to force a tie break.

5-4 - A 116mph second serve from Haas gives him the early ascendency in the game, and a huge double fault reflects the aggression of his approach. Federer pegs him back to 40-30 with a solid backhand, but a good first serve enables the German to hold once more. This first set is very finely poised.

4-3 - Haas moves serenely to 40-0, with a second call for Hawkeye from Federer unable to prevent his steady progress. The German looks very composed as he closes out the game with a big first serve, and he holds to love at 4-3.

3-2 - Federer again manages to sneak his way to 0-30 with two crisp returns, but a good first serve and a clean volley level the game up for Haas. An ace down the T and a sliced backhand into the net from Federer give the German his third service hold.

2-1 - An exquisite backhand pass from Federer gives him 0-15, but Haas regains recovers from 0-30 with an ace outwide. Another good first serve to the body of his opponent gives Haas another solid hold to keep the first set going with serve early on.

1-0 - Haas fires a good first serve to Federer's body to move to 40-30, but the Swiss strikes a backhand smash down the line to take the game to deuce. The German is afforded no cheap points as he keeps his composure to hold in the opening game of the match - the atmosphere is building steadily on Centre Court.

- - The number two seed leads the pair's head-to-head record 9-2, including three victories on grass. The latest was at Wimbledon in the last 16 in 2007, with further wins at Halle in 2005 and 2006.

- - To read about how the 24th seed dispatched of the Serb in the quarter final click here to view the full match report

- - Tommy Haas has dropped four sets on his way to the semi-finals and, most notably the German beat fourth seed Novak Djokovic in the previous round. Click here to view Haas's profile page

- - It is forecast to be another sunny afternoon in SW19, with temperatures reaching 26 degrees. Heavy showers were predicted for this morning and that was wrong, so fingers crossed it will stay dry as the day wears on.