MARINA BAY, Singapore -- In a championship battle that could easily be decided by small mistakes, Sebastian Vettel made another on Friday night in Singapore. As he rounded the penultimate corner toward the end of a quick lap, he clipped the barrier on the exit with his right rear wheel. The car returned to the pits leaking hydraulic fluid, and with it his session was over.

In the grand scheme of things, it was pretty small error -- the sort that comes with the territory during a practice session on a street circuit -- but given his season so far, it was another unnecessary concession to his title rival, Lewis Hamilton. The early exit from Friday night's practice session meant he was unable to get a feel for Pirelli's tyres on heavy fuel and he will therefore have to rely on the data of his teammate Kimi Raikkonen to build his race strategy with his engineers.

Singapore is a must-win race for Sebastian Vettel after a series of mistakes earlier in the year. Mark Thompson/Getty Images

But if Vettel is feeling the pressure, he didn't show it. As ever, his comments to the media after second practice in Singapore were calm and collected.

"The bad bit, obviously, was the touch with the wall which made the session come to an end," he said. "We lost some time, not ideal, but nevertheless I think the feel that I had for the car was alright. I think we can improve from where we are, so it should be fine tomorrow."

Sebastian Vettel's errors in 2018 Azerbaijan: Threw away at least two places with a misjudged overtake on Valtteri Bottas for the lead. Given Bottas' retirement a lap later it was a race he could have won. Finished fourth. France: Collided with Bottas while fighting for second place at the start. Finished fifth but a podium was possible. Austria: Penalised in qualifying for failing to make way for Carlos Sainz. Started sixth and finished third but could have won from a higher grid slot given that both Mercedes retired. Germany: Spun off the track in wet conditions while holding a comfortable lead in the race. Scored no points, should have won. Italy: Got caught up in a collision with Hamilton on the opening lap. Fought back to fourth place but should have challenged Hamilton for victory.

Vettel rarely shows weaknesses outside the cockpit, but when he has been inside it this year, they have often been clear to see. Five incidents stand out as avoidable mistakes this season (see sidebar), and combined they have cost him more than 60 points. The most costly -- in terms of points and from a psychological point of view -- was at Hockenheim and, judging by his comments during a media session on Thursday, the mistake still has roots in the back of his mind.

"I think it is normal that you do a lot of races and some you feel you could have done better or should have done better for different reasons," he said. "I think there were also other races where we shouldn't have done so well and we did. But for sure the worst one was Germany.

"I think most important is that I know what happened and I can explain it, and then everyone is free to have their own views on what happened. I would have loved to win in Germany, for sure, but I'm not too bothered, and I'm generally looking forward and not focusing on what we all could have done differently to avoid what happened."

Despite the errors, the year's championship situation is still recoverable. Vettel has a 30-point deficit to Hamilton, but he's no stranger to playing catch-up. In 2010, he came back from a 31-point gap with six races remaining to win the championship, and in 2012, he recovered a 39-point deficit in the space of seven rounds.

The good news for Vettel is that, as in 2010 and 2012, he has the fastest car on the grid this year. Back then, it was the Red Bull, but right now it is his Ferrari. Hamilton's wins against the odds in Hungary, Germany and Italy muddy the championship picture slightly, but in reality, Ferrari has held a performance advantage over Mercedes since the British Grand Prix in July.

Vettel is aware of his advantage, and on Thursday made a statement that could be construed as either subtle confidence or lingering self-doubt. Asked if he couldn't afford to lose any more points, the four-time world champion admitted the biggest threat to his championship challenge was himself.

"I think the biggest enemy is me," he said. "I think we have a great car, I have something to play with and we have all the chances to do it in our way. Obviously, he is the leader at the moment, he's the one ahead and he is the one to beat, but I think we have all the chances, and how much they could be better by now and so on is a different question.

"We still have a very good chance, and as I said, we will be our first enemy and not him as a person or them as a team. I think we need to look after ourselves, and if we do that, we have a good chance to do well and win races and things look good."

Meanwhile, Hamilton has barely put a wheel off line this season. His performance at a handful of races at the start of the year left a little to be desired, but in terms of race-changing mistakes, none stand out. And Hamilton's consistency puts an even brighter spotlight on Vettel.

Combine that with the internal pressure at Ferrari to win its first drivers' championship in over 10 years and the weight of expectation is colossal. Realising the mounting pressure on his driver, team principal Maurizio Arrivabene did his best to shoulder some of that pressure in a news conference on Friday.

The turning point in the championship? Sebastian Vettel's dramatic crash in Germany handed victory on a plate to Lewis Hamilton and Mercedes Dan Istitene/Getty Images

"You call it mistakes, but if you look in Formula One, everybody is making mistakes," the Ferrari boss said. "Bigger or smaller. If we are a team, we fail and we win together, so I don't want to point my finger at Sebastian. I mean, nobody was happy after Monza, but think about the rest of the team.

"If in Monza I was pointing my finger at Sebastian, think about a problem on aero, a problem on the pit stop, a problem on the engine. The guys, they are responsible for the different areas, they could think, 'OK, if he's pointing the finger at Sebastian, next time it's my turn.' It's not what I want.

"The only mistake you see in front of you is me. I'm responsible for the team. When the result is not coming, it's my responsibility. Not the responsibility of Sebastian or the engineer or the responsibility of the mechanics. It's my responsibility. If you want somebody to blame, he's in front of you."

But words will only go so far. A win in Singapore is what Vettel needs to close the chapter on his accident-riddled European season and start narrowing the gap to Hamilton over the remaining seven races. Given the latent performance in his Ferrari, and his form at this circuit over the years, it is entirely achievable regardless of the mistake on Friday night. But make another error and his championship challenge could come tumbling down.

No pressure, Sebastian ...