Lewis Hamilton led the first practice session of the Hungarian Grand Prix, while Sergio Perez walked away unscathed from a crash in searing heat on Friday.

Many drivers wore tributes to Jules Bianchi, with race stickers such as "Ciao Jules" or "JB 17" on their helmets. Bianchi died last Friday from injuries sustained last October in a crash at the Japanese GP.

Formula One tire supplier Pirelli tweeted "sarai sempre con noi" (you will always be with us) in honor of the French driver, who died at the age of 25, and was buried on Tuesday in his hometown of Nice.

Lotus driver Romain Grosjean, a close friend of Bianchi's, had "JB" and "Never Forget" engraved on his helmet.

There was a major scare when the red flag came out one hour into the session as Perez flipped his Force India car on turn 11, with the rear skidding out from under him and sending him into the barriers and toppling slowly over.

Fears for Perez's safety were quickly eased as he waved to fans at the Hungaroring on his walk to the medical center for a mandatory check.

"Checo returns to the garage waving to the crowds in the stands after a quick check with the doctors. Thumbs up, a big relief," his Force India team tweeted.

Other teams sent tweets of encouragement and relief that the 25-year-old Perez was fine. He was able to conduct a television interview soon after, where he said dirt on the track caused him to lose control of the rear of the car.

The track temperature was 59 degrees (138 F), the hottest anywhere in F1 for two years, according to Pirelli.

But that was little deterrent to Hamilton, who loves racing on the tight and sinewy 4.4-kilometer (three-mile) Hungaroring, winning four times here.

The F1 champion needed little time to shoot up the leaderboard, and then went even faster, finishing .109 seconds quicker than Mercedes teammate Nico Rosberg, and .671 ahead of Ferrari's Kimi Raikkonen.

The veteran Finn lost his front wing, which dropped off a few minutes from the end of the session, bringing out the red flag for a second time.

"I don't know what happened," Raikkonen said on team radio.

There was hardly time for more than one lap once the session resumed.

There was a second practice late Friday, and qualifying on Saturday.

In the overall standings, Hamilton leads Rosberg by 17 points, and four-time champion Sebastien Vettel of Ferrari by 59.