The 12th round of the 2017 FIA Formula One World Championship began with practice Friday at Circuit de Spa-Francorchamps as teams prepared for the Belgian Grand Prix Sunday. Two 90-minute sessions – FP1 and FP2 – on the 7.004-kilometer (4.352-mile), 19-turn circuit were run under disparate weather conditions.

Nestled in the Ardennes region of southeast Belgium, Spa-Francorchamps is the longest track in Formula One and produces some of the sport's highest speeds, with average laps eclipsing 220 kph (137 mph). The venue is also known for quickly changing weather, and that was on display Friday, with FP1 run under a warm and sunny sky while FP2 began cloudy and ended with rain.

Haas F1 Team drivers Romain Grosjean and Kevin Magnussen attacked the undulating circuit, each logging 20 laps in FP1 and 15 laps in FP2. The duo ran similar programs throughout the day, beginning FP1 on the Pirelli P Zero Yellow soft tire before switching to the slightly grippier Red supersoft compound.

Magnussen set the 16th quickest time in FP1 with a 1:48.615 on his 11th lap and Grosjean followed in 17th with a 1:48.626 secured on his 15th lap. Both drivers set their quick times utilizing the Red supersofts.

Leading the way in FP1 was Scuderia Ferrari driver Kimi Raikkonen with a fast lap of 1:45.502. Just .053 of a second behind him was Mercedes pilot Lewis Hamilton while Raikkonen's teammate, Sebastian Vettel, was third quickest, .145 of a second short of earning quick time.

Speeds picked up and lap times dropped in a rain-shortened FP2, with both Haas F1 Team drivers able to better their times from FP1. Grosjean wrapped FP2 as the 13th-quickest driver with a time of 1:47.285, which was 1.341 seconds better than his best lap in FP1. His quick time came on the 10th of his 15 laps shod on a set of Purple ultrasoft tires. Magnussen shaved 1.059 seconds off his FP1 time with a 1:47.556 earned on his ninth lap, also while utilizing the ultrasoft tire. He ended the session 16th overall.

Light rain moved in over turns five and nine with 30 minutes remaining before heavy rain with 20 minutes to go washed out the rest of FP2.

Atop FP2 was Hamilton, who pipped Raikkonen for the top spot by .262 of a second with a lap of 1:44.753. Hamilton's Mercedes teammate, Valtteri Bottas, was third to sandwich the Ferrari driver, .427 of a second off the time set by Hamilton.

The track record at Spa remained untouched, but it appears set to fall when qualifying begins Saturday. Jarno Trulli currently owns the fastest lap at Spa – a 1:44.503 set in his Toyota during the second round of qualifying for the 2009 Belgian Grand Prix. Hamilton's quick FP2 time was just .25 of a second shy of eclipsing Trulli's eight-year-old mark.

Romain Grosjean: "Generally, we've been struggling a little bit on low downforce circuits and that seems to be the case here again at Spa. We're trying to find the setup between drag and downforce, but we're struggling a bit with it. We're going to see where we can do better tonight, work hard, find the last few tenths and decide on the downforce level – which will be a big decision for us. It's a tricky one getting everything to work and the right top speed. Hopefully, tomorrow we'll have slightly more performance and that'll put us in a decent place."

Kevin Magnussen: "I think we've got a lot of information from today on different things. There's a lot to look at and analyze for tomorrow, so I'm keeping positive. I wouldn't read too much into today. The challenge for tomorrow is looking at downforce levels and finding the right setup. That's what's going to be key. It was good fun driving these cars here, no surprises, but good fun."

Guenther Steiner: "We always wanted to test two different levels of drag on this track, so we did that and came out with what we need to do. We had a little bit of an issue in FP2 at the beginning, with the DRS system, which was sorted pretty quickly. Tomorrow we go out again and we know which drag level to use and we'll try to get a good setup for qualifying."

Check out our Friday gallery from Spa, here.