It looks like Rosberg is now on heavier fuel as he laps two seconds off the pace. It's possible Alonso will finish this session on top.
A battery issue for Vergne and Gutierrez also has problems and will not be back out again in this session.
@maximus: Things haven't been the same since the financial crash in 2009. It's not easy to get companies to throw cash at a sport like F1, although there are still some success stories up and down the paddock. McLaren claims to be closing on a title sponsor, but we've yet to have an announcement.
@PolePosition: Alonso's time is impressive, but Mercedes has often held something back on a Friday. To be completely honest, I can't see it being anything other than a two-way fight for pole.
@rockedin123: You could ask the same about any development on a car. These things take time, the cars are prototypes and getting the most from them takes research investment and testing.
@Raja: It's a big question. Honda are taking their return very seriously, but the biggest issue I see is that McLaren looks likely to be the only team using Honda power in 2015. If you consider how much Renault struggled for mileage at the start of the year with four teams, Honda really have to hit the ground running from the start of pre-season testing.
@kkunakorn: He had an engine issue earlier in the session, so the Ferrari team has been working on it since.
@Carlito: Hopefully 12. If Fernandes does get out of F1 he will want to sell the team if possible otherwise it represents a huge loss since 2010.
Less than a minute remaining and Alonso's time looks safe at the top of the timesheets.
As I type, Alonso runs wide at the final chicane, but this has been a positive session so far.
@rob: We don't know for sure yet, but rumours suggest Ferrari is likely.
@jee1: Raikkonen had an engine issue early in the session and it's only FP1. So, no, it's not fair to say that.
@Dane: I'd still be surprised if Forza Rossa are on the grid next year. But you never know and they are likely to go the Ferrari route if they do. As mentioned earlier, Honda will be looking for a second team, certainly by 2016.
So, Alonso finishes the session on top, 0.016s clear of Hamilton in second place. Rosberg third ahead of Vettel and the Williams of Bottas.
A promising start for Ferrari, but we'll know more about what Mercedes is holding back in FP2.
Thanks for joining us for FP1. We'll be back in two and half hours for FP2. Make sure you join us.