Hamilton fastest, Vettel penalized at US Grand Prix practice

AUSTIN, Texas (AP) — Even in the rain, Lewis Hamilton seems to be in unbeatable form.

As for Ferrari driver Sebastian Vettel's fading title hopes, another unforced error may doom his chances once and for all.

Hamilton's Mercedes posted the fastest lap of Friday's soggy practice sessions at the U.S. Grand Prix, a race where he can clinch a fifth career championship on Sunday. Hamilton sloshed around the Circuit of the Americas in 1 minute, 47.502 seconds in the morning, then sat out most of the afternoon session when rain again soaked the track.

Vettel was hit with a three-spot starting grid penalty for driving too fast under a red flag in the morning session.

The flag came out when Sauber's Charles Leclerc, who will be Vettel's teammate next season, spun off the wet track into the grass. When he drove back on, the rear tires spun and dragged gravel onto the track. Race officials stopped the session for several minutes for cleanup.

Vettel was in the middle of a lap when the red flag was posted and was penalized for not slowing down quickly enough. That means even if he wins the pole position for Sunday's race, he will start in fourth. The best he can likely hope for is that Hamilton has some kind of qualifying calamity.

Vettel violated a rule put in place this year that was designed to ensure drivers slow down to safe speeds under a red flag. Similar penalties were applied to Force India's Esteban Ocon and Red Bull's Daniel Ricciardo earlier this season.

This time, it could decide the season championship.

Vettel had to be penalized "to be consistent with previous decisions," the stewards said.

Vettel met with the stewards before the penalty was assessed and was allowed to explain what he thought happened.

"I think I slowed down," Vettel said. "I had a good look around to see what's going on ... From the inside of the car, I slowed down enough. In my opinion it is not the right thing. If there is a car behind you it might run into you, but it is more important you don't get a penalty."

If Hamilton wins Sunday, Vettel must finish second to push the championship another week to Mexico City. Any result that leaves Vettel eight or more points behind his rival and Hamilton will win the title. Hamilton is gunning for his sixth win in seven years at the Texas track and his 10th of the season.

The rain that swamped the track was reminiscent of storms in 2015 that shortened qualifying. Hamilton won that year to clinch his third career championship.

The British driver looks on form to do it again. He has a 67-point lead over Germany's Vettel with four races left. Hamilton has won the Texas race four years in a row and has started no lower than second in that stretch.

The rain kept drivers huddled in their garages most of the afternoon. Vettel ventured out with out with about 12 minutes left and Hamilton spun only a couple of laps in the final eight minutes, but couldn't run a faster time than his morning lap. Mercedes teammate Vallteri Bottas was second-fastest on the day, 1.3 seconds behind Hamilton in the morning.

More rain is forecast for Saturday's final practice and qualifying. The skies are expected to clear for Sunday's race.