Ferrari’s Sebastian Vettel admitted Thursday he had been his own worst enemy in his Formula One title duel with Lewis Hamilton. Vettel has made a series of driving blunders to leave him 30 points behind the Englishman as they go into this weekend’s Singapore Grand Prix.

“The biggest enemy is me,” the German told reporters at the Marina Bay street circuit. Vettel’s lapses have cost him points at races in Azerbaijan, France, Germany and Italy that could have seen him leading the championship with seven of the 21 races to go.

Instead Vettel is playing catch-up and he knows he cannot afford any more gaffes. “It is pretty straightforward,” he said. “He (Hamilton) is ahead at the moment so he is the one to beat. But we have had the chances. It doesn’t help when you start from the front row and you end up facing the wrong way,” he said of his first lap spin at Monza two weeks ago, which left him at the back of the pack.