(CNN) -- Ferrari driver Fernando Alonso set the pace during practice for Sunday's Belgian Grand Prix.
The Spaniard was quickest in both the morning and afternoon sessions as his rivals for the drivers' championship lagged behind.
Alonso posted a lap of two minutes, 0.797 seconds in a rain-hit morning session but improved to record a second lap of one minute, 49.032 seconds in the more favorable afternoon conditions.
Force India's Adrian Sutil was 0.125 seconds behind Alonso, while McLaren's Lewis Hamilton came third. Drivers' championship leader Mark Webber was left trailing by a full 2.6 seconds.
Webber told Formula One's official website: "Today was a bit of a messy day with the changing conditions, but it was actually pretty good for us. We got some good information to go through and I'm looking forward to tomorrow.
"There are a few quick guys out there, but we're not slow either. It's hard to get a feel for what everyone's doing with the changing weather. It's a beautiful track here, it's special - today we got to sample it in all conditions."
After the morning session was dominated by rain, the afternoon stint was delayed by a red flag, then concerns for the crowd after spectators appeared to climb onto fences for a better view of the track.
It led to a chaotic end to the final session, but Alonso managed to complete his quickest lap of the day shortly before time ran out.
Alonso told the Formula One website: "The impression one gets on Friday does not always get confirmed on Saturday and Sunday, therefore we have to evaluate today's results with a lot of care.
"Having said that, it has definitely been a positive day, because the car seems to respond well in all track conditions that we encountered today."
Renault's Robert Kubica came fourth, Alonso's teammate Felipe Massa was fifth, Sebastian Vettel came sixth in the Red Bull, while Jenson Button was seventh overall -- four places behind McLaren teammate Hamilton.
"The weather made it a bit of an up-and-down day," Hamilton said. "It started off very wet, so we didn't do too much running in the morning. But we got a few more laps this afternoon on the intermediates and then the option tire.
"Because the rules don't allow us to use too many wet-weather tires - we only have three extremes and four intermediates - we really need to look after them, so we were very cautious, just in case we need to use them later on in the weekend.
"We're definitely making small steps forward. This track does seem to suit our car better [than in Hungary], but let's not get ahead of ourselves.
"If it rains, then we seem to be competitive, but we have realistic expectations for this weekend - I didn't score in the last race, so it's important that we get more points on the board on Sunday."