MEXICO CITY (AP) Lewis Hamilton won the Mexican Grand Prix with the help of a wide turn through the grass and dirt at the first corner.
It was a crucial victory for the defending champion if he is to catch Mercedes teammate Nico Rosberg in this season's title chase with just two races left.
But several drivers questioned why Hamilton wasn't penalized for going off track and returning with a huge lead. The move came when Hamilton locked his right front brake coming out of the long straight off the start.
''Very surprised by that. Massive advantage,'' said Force India's Nico Hulkenberg, who started fifth and had a good view of Hamilton's drive into the first turn. ''I think he was going well off the track. He was far, far from making turn one and two ... That it's not even being looked at is amazing to me.''
Hamilton started on pole position and the maneuver helped him stay ahead of Rosberg. It was critical for both the race and the chase for the season championship.
Race officials chose not to review Hamilton's move, but did look at a bump between Rosberg and Red Bull's Max Verstappen at the same turn that briefly sent Rosberg into the grass as well. No penalty was assessed in that case.
Verstappen was later penalized 5 seconds for running wide into the grass at the same corner as Hamilton's drive-off. Verstappen's wild ride came in a late-race duel for the third with Ferrari's Sebastian Vettel, and the penalty cost him a podium finish.
''Lewis gained a massive advantage (at the start),'' Verstappen told Sky Sports. ''I didn't gain an advantage. When I came back on track I was the same length in front so I think it's ridiculous.''
Hamilton insisted they were different racing situations.
''I think I was still in the lead going in. I was still in the lead going out,'' Hamilton said.
Red Bull's Daniel Ricciardo, who finished third, wasn't so sure.
''How you can be leading, lock the brakes, go off and come out in front?'' Ricciardo said. ''I think he deserved the penalty. I think anyone who does that deserves a penalty.''