There was a moment during the second free practice session here yesterday afternoon when Red Bull's rivals involuntarily issued collective gasps of dismay.
Vitaly Petrov had not long set the fastest lap time of 1min 24.786sec when Sebastian Vettel sliced it down to 1:22.826, 1.96sec faster. It got worse for them when Vettel's team-mate Mark Webber, the runaway winner from pole position here last year, reduced that to 1:22.470. But with half an hour to go Lewis Hamilton confirmed the improvement that McLaren have made to their car with up to 12 upgrades, by pushing between them on 1:22.509, just 0.039sec shy of Webber.
As far as fans are concerned, this is what F1 needs desperately, potential serious competition for the world championship-winning team from Milton Keynes. But the Spanish spectators would have been a lot happier had Fernando Alonso done better than fifth place, on 1:23.568, in his modified Ferrari, while doubtless the Germans would have wanted Nico Rosberg and Michael Schumacher in their improving Mercedes to have done better than 1:23.586 and 1:23.981 respectively.
These days teams can't afford to sandbag on a Friday, and though Red Bull have a habit of pulling something out of the bag in the final qualifying session on a Saturday, the times at the top of the sheets are encouraging for McLaren's chances tomorrow. And thus far in 2011 Ferrari have habitually raced better than they qualify.
"It's difficult to get an accurate read on pace," Hamilton admitted. "We stuck to our programme today and didn't appear to be too far off, but you never know what fuel loads or engine levels the other teams are running. Still, we got some good data and made some positive improvements so, in all likelihood, we look as competitive today as we have in the past.
"We put a new front wing on and it naturally appeared to be a little bit better. But when I spoke with Mark Webber just now, he wasn't like, 'Wow, you were quick!' I don't think that those guys are sweating just yet."
Team-mate Jenson Button, fourth on 1:23.188, added: "This morning was spent running through the new systems on the car; this afternoon was the time to push a bit harder and get a proper feel for things. I'm not particularly happy with the balance but I'm going to work to improve that overnight. There's more pace in the car, we've just got to unleash it and find a balance that I like."
The mood was also grounded at Ferrari, with the gap of more than a second between Webber and Alonso. "My first impression is favourable: I think we have made a step forward," the Spaniard said. "It's always difficult to judge the gaps in free practice because there are always differences between one car and the next. But the chances of fighting for a podium are even more likely here than they were in Turkey."
Hamilton's hopes lie in qualifying well and making the most at the start. "The problem is, when Vettel starts on pole position it's easy because he has clear air. It's pretty much done and dusted by Turn One because he's able to look after his tyres and his engine. When you get stuck behind a car that's slower than you, the question is, do you back off and save the tyres? I tend to try and get past them as quick as possible, use the tyres in the early stages to get by. But at the last race it took me forever to get past Jenson, and once I finally got past, my tyres were destroyed. If I can get the car on the front row, those problems will pretty much disappear."
The 2008 world champion has already been connected to a Red Bull drive next season, but yesterday Ferrari team principal Stefano Domenicali refused to rule out a future role for him with the Italian team, notwithstanding his enmity with Fernando Alonso (who yesterday was revealed to have signed a new contact until 2016), when they were team-mates at McLaren in 2007.