Qualifying in Spain proved to be a tale of two very different rubber compounds: anyone who found themselves on the wrong type of tyre at the crucial moments was in for a very rude awakening and an early day of it. Those who got it right were about to become the stars of the day and set themselves up for a great start to the Spanish Grand Prix.

Most of the runners initially tried toughing it out on the harder compound when Q1 got underway, with Lewis Hamilton setting the early benchmark of 1:23.989s in the McLaren, a perfectly decent showing especially considering just how much trouble everyone was having finding grip on the Circuit de Catalunya on Saturday.

But it was when Williams' Pastor Maldonado made the first flying lap on the much softer option tyres and went six tenths of a second faster that it was clear just how big the speed differential really was between the two different available tyre compounds. After that, all bets were off: even Lewis Hamilton himself was forced to come back out for a second run before the end to protect himself from the danger of everyone else surging past him in the timesheets and leaving him with egg on his face.

Lotus F1 and Red Bull had seen this coming, and opted out of the first rush onto track with the hard tyres knowing that it would prove futile, and instead waiting to go out for a single run on the soft options later in the session. It proved a canny decision, maximising the number of new tyres available to them for the race while still putting all four cars safely through to Q2.

Most of the other leading contenders then went on to put in sufficiently fast lap times to achieve their safe passage into Q2, with the biggest battle in the closing minutes coming down to Bruno Senna's increasingly desperate effort to match his Williams team mate's earlier time-topping performance and instead left battling to make it into the top 17 in order to progress. Finally the pressure showed, and the car slipped into a spin after getting unbalanced over the kerbing meaning that Senna ended up in the gravel at turn 12 and out of qualifying.

Also out at this stage were the usual suspects of Caterham duo Vitaly Petrov and Heikki Kovalainen, Marussia pairing Charles Pic and Tim Glock, and HRT drivers Pedro de la Rosa and Narain Karthikeyan. The Indian driver's headaches aren't over yet, either - he failed to make the 107% cut-off time by almost 3s and his lap of 1:31.122s was a considerable way off the rest of the field, forcing him to throw himself onto the mercy of the race stewards to allow him to start the race on Sunday.

With Q1 over, the teams now knew what to expect in Q2 and this time no one was wasting their time with hard compound tyres. It was soft options all the way down, although the initial circulations were almost invariably undertaken on used sets in order to give them a spare set later down the line.

Hamilton immediately carded an impressive lap of 1:22.977s which looked like pole position might be a done deal there and then. Indeed his time held on to the top spot remarkably well, and while Mark Webber and Nico Rosberg soon set times somewhere in the same neighbourhood it was clear that the McLaren wasn't under any immediate threat.

Once again the Lotus F1 drivers Romain Grosjean and Kimi Raikkonen bided their time, eventually coming out with six minutes to go and right away going safe by slotting into second and third places respectively behind Hamilton. As the Q2 time ticked away, the speeds started to pick up and suddenly big names like Sebastian Vettel and Fernando Alonso were on the wrong side of the top ten and had to go back out and push still harder.

Alonso soon went safe into fourth, ironically demoting his Ferrari team mate Felipe Massa out of Q3 in the process. But that was just the start, as suddenly all hell broke loose on the timing screens with times tumbling and positions scattering like startled pigeons in all directions. The minute you thought you knew who was through, it all changed again - there were some 14 changes in the last four minutes before the dust finally settled and the view finally became clear.

Despite improving his time by another half a second, Hamilton had been deposed from the top spot by Pastor Maldonado, who really did seem to have genuine fire in his belly in Barcelona as he put in a searing lap of 1:22.105s. But Hamilton was still perfectly safe, which was more than could be said for his team mate Jenson Button who had been complaining throughout the session about understeer and lack of grip at the front, but had still seemed to have done well enough to at least get through to Q3.

That all changed in the final seconds, however, as a little cloud cover at the key moment suddenly cooled the track and pumped a little more grip into the surface, which meant that the Mercedes and Sauber pairings all put in suddenly much0improved laps that knocked the timesheets for six. Making the grade for Q3 were Maldonado, Hamilton, Grosjean, Sergio Perez, Raikkonen, Alonso, Rosberg and Michael Schumacher, along with Sebastian Vettel who squeaked through in ninth position despite clearly lacking straight line speed compared to many of the cars out there.

Out at the last minute was Jenson Button, and also Mark Webber who admitted afterwards that the team had simply been too complacent and caught out by that last furry of flying laps, and not out on the track to strike back when they needed to. They joined the two Force India cars and both Toro Rosso drivers on the sidelines, along with Felipe Massa who will start from 17th place on the grid.

A peculiar Q3 topped off a breathless, exciting qualifying session. It started with the unusual sight of Sebastian Vettel queuing at the end of pit lane to get out on track; but when he did, he merely recorded a few mediocre sector times before coming back into the pits. Michael Schumacher did the same.

Then finally Lewis Hamilton came out and laid down his challenge: 1:22.560s, which immediately seemed like pole position done and dusted. But that proved not to the the case, as laps near the end of the session saw first Fernando Alonso and then Pastor Maldonado go faster than the McLaren. Were we about to see a real shock pole position for Williams, after so many years in the wilderness?

Some sense of normality was restored just seconds later when Lewis Hamilton crossed the line on his final flying lap of the day and the time of 1:21.707s was sufficient to restore the natural order of things as the chequered flag came out. However, there was one final touch of drama to follow: Hamilton received orders from pit lane to park the car immediately with an unspecified technical problem, and as he did so - right in front of the heartland of the Fernando Alonso fan club - the spectators cheered wildly at this possible change in fortunes for the British racer.

Assuming that the issue is nothing serious, Hamilton will line up for the start of the Spanish GP with Pastor Maldonado alongside him; but if anything causes Hamilton to lose grid positions, then Alonso - currently in third place - could be boosted onto the front row instead.

Lotus duo Romain Grosjean and Kimi Raikkonen recorded the fourth and fifth fastest times, with Sergio Perez and Nico Rosberg the only other drivers to set times in Q3. Vettel and Schumacher never came out again in the session after laying down some basic sector times early on, and Kamui Kobayashi was unable to participate in the session after his Sauber had been ordered to a halt at the end of Q2 following a hydraulics leak.

Drivers and teams (and quite a few fans) might not like the impact that the Pirelli tyres are having on Grand Prix racing at the moment, but no one can deny that - thanks to their strategy of the tyre choice available to teams at Catalunya - the starting grid for tomorrow's race just got very interesting indeed, with it now being anybody's guess as to who will benefit most from the scrambled order when the lights go out on Sunday.