Final positions after 66 laps: 1 F Alonso (Renault)
2 M Schumacher (Ferrari)
3 G Fisichella (Renault)
4 F Massa (Ferrari)
5 K Raikkonen (McLaren)
6 J Button (Honda)
7 R Barrichello (Honda)
8 N Heidfeld (BMW Sauber)
Lap 66: Alonso sends the Barcelona crowd into a frenzy as he becomes the first Spaniard to win on home soil, finishing over 18.5 seconds ahead of Ferrari's Schumacher and extending his lead at the top of the championship standings.
Alonso's Renault team-mate Fisichella claims the final podium place, finishing a further 5.4 seconds back. Massa is fourth with a huge 27-second gap over Raikkonen, while Button claims sixth.
Lap 62: Pole-sitter Alonso looks set for his first victory on home turf as he comfortably leads with just a few laps remaining in Barcelona. Ferrari rival Schumacher, who won the last two races in Imola and Nurburgring, is 17.2 seconds behind.
Lap 56: Schumacher has slipped to 15.7 seconds behind Alonso and seems to be resigned to settling for second at the Circuit de Catalunya.
Lap 53: Button is really putting pressure fifth-placed Raikkonen, whose McLaren car is making less than healthy sounds.
Lap 49: Toro Rosso's Speed is out of the race and as his car is pushed intot he garage and into retirement.
Lap 46: Schumacher finally comes in for his second stop as Alonso slips back into the lead. Lower down the grid, Coulthard is in 16th, having started the race in 21st, while Button remains sixth - two places ahead of Honda team-mate Barrichello.
Lap 40: Alonso comes in for his second stop and the Renault pit crew does well to get the Spaniard back on track just behind Fisichella. But Schumacher is the new race leader and will be hoping to squeeze the most out of his fuel load and stretch his advantage before a second stop.
Lap 35: Alonso continues to set a blistering pace as he attempts to put distance between himself and championship rival Schumacher. The gap is up to 12.4 seconds with the Spaniard piling through the laps.
Lap 32: Ralf Schumacher looks to be out of the race as he joins Montagny and Montoya on the retired list. The German blames 'electronic failure'.
Lap 30: Alonso has a 9.6-second lead over Schumacher, while Fisichella is a further 8.9 seconds back. Felipe Massa lies fourth, ahead of Raikkonen. Britain's Jenson Button has also made progress, leapfrogging Honda team-mate Rubens Barrichello to take sixth.
Lap 23: Schumacher finally comes in for his first stop - a full six laps after Alonso - and makes a vital breakthrough, sneaking just ahead of Fisichella on his return to the track. Now nothing stands in his way as he challenges race-leader Alonso.
Lap 21: Schumacher is ahead of Alonso but still has to come in for his first stop, along with Raikkonen, who lies in third.
Lap 17: Renault's Alonso seems to be on a two-stop strategy and is making the most of his early lead over Michael Schumacher by being first to come in the pits. But it is more disappointment for Juan Pablo Montoya who compounds Saturday poor qualifying by spinning out while in 10th position.
Lap 16: Toyota driver Ralf Schumacher comes off worse in a scrape with team-mate Jarno Trulli for eighth place. The German is missing half his front wing and is forced to come into the pits.
Lap 13: Alonso leads by 8.7 seconds, much to the delight of the Barcelona crowd. Team-mate Fisichella is next with Schumacher a further two seconds back.
Lap 11: Super Aguri have plenty to worry about as both drivers come into the pits. Yuji Ide's recent replacement, Franck Montagny, suffered a spin on turn four and looks set to denied a race finish. Team-mate Takuma Sato also comes in to have some dirt cleared from the car's side-pods.
Lap 8: David Coulthard seems determined to see out his 200th Grand Prix in style as he lies in 17th, having started 21st in the grid.
Lap 7: Race leader Alonso continues to extend the gap over Ferrari rival Schumacher with his fastest lap yet. The Spaniard clocks 1:17.416 to be a full 8.7 seconds ahead of the German, who is lying in third behind Fisichella.
Lap 3: Tago Monteiro's hopes are dashed early as the Portuguese driver slides his Midland out of control on turn five. Meanwhile Toro Rosso's Scott Speed has moved up from 17th to 13th.
Lap 1: It is a great formation start by Renault as Fernando Alonso and Giancarlo Fisichella lead the way.
But the biggest beneficiary of the first lap is Kimi Raikkonen who navigates past two Hondas and two Toyotas to fifth after starting ninth on the grid.
1300: The parade lap is under way. The track temperature is 36C and rising.
1250: The teams are making their final preparations and the drivers are putting on their helmets as just 10 minutes remain before the start of the race.
1232: The pit lane opens and the cars begin to leave to form up on the dummy grid.
1220: With 40 minutes to go, the weather at the Circuit de Catalunya is warm and sunny with an air temperature of 28C and humidity of 38%.
World champion Fernando Alonso goes in search of victory on home turf after clinching pole position in Saturday's qualifying.
The Spaniard leads an all-Renault front row on the grid after team-mate Giancarlo Fisichella was second quickest, ahead of championship rival Michael Schumacher.
Ferrari's Schumacher is 13 points behind Alonso in the championship standings and will be looking to narrow the gap in Barcelona.
Meanwhile, Sunday's race marks David Coulthard's 200th Grand Prix, but the Scotsman will start in 21st position on the grid after crashing out in qualifying.
Only Jacques Villeneuve starts behind Coulthard after incurring a 10-place penalty for an unscheduled engine change.
Elsewhere, Juan Pablo Montoya faces a stiff challenge on Sunday. The McLaren driver failed to make the top 10 shoot-out in qualifying and had to settle for 12th on the grid.
Team-mate Kimi Raikkonen won last year's race, finishing ahead of Alonso and Jarno Trulli in third.