Mercedes team principal Ross Brawn has expressed fears of another Sebastian Vettel walkover in Sunday's Korean Grand Prix.

Brawn’s comment followed a qualifying session in which Vettel secured his third successive pole position, sixth of the year and 34th of his Formula One career.

After three straight wins to open up a 60-point cushion over his nearest rival in Ferrari's Fernando Alonso in the title race, the concern in the paddock is Vettel will again romp to victory.

That was certainly the case a fortnight ago under the lights of the Marina Bay Street Circuit in Singapore, where Vettel crushed the opposition with a 32-second triumph over Alonso.

Such dominance was sparked by a blast immediately after the safety car period, when he opened up a 30-second gap over 15 laps to ensure he could pit again without losing his lead.

At the Korea International Circuit, Vettel has behind him Mercedes duo Lewis Hamilton and Nico Rosberg in second and fourth, with Alonso fifth, the latter pair moving up a position with Mark Webber serving a 10-place penalty.

But, with Vettel in commanding form, Brawn can sense what might be on the horizon.

“If we look at Friday (with Hamilton on top in practice) then we can expect quite an exciting race,” Brawn said.

“The difficulty is projecting what we saw on Friday into the race because we were encouraged by our race pace.

“We had a particularly good (long) run, but I don’t think we saw Sebastian’s run.

“He stayed on the soft option (tyre) and was obviously managing them on Friday, so we haven’t seen his true pace yet. But hopefully we won’t get a repeat of Singapore.”

Vettel, who finished two tenths of a second quicker than Hamilton, was even able to abort his final flying lap as no-one came close to challenging his first run.

“I had a very, very good lap in Q3, my first attempt,” Vettel said. “I knew it would be tricky to beat that time – for myself. I tried again, but I caught Kimi (Raikkonen) on the warm-up lap and was a little bit too close.

“We didn’t have that much time in hand to drop back further, so it was not ideal, but fortunately the first lap was good enough.

“Mercedes are very strong, but we’ve got the balance right this weekend, improving the car from Friday when I wasn’t entirely happy.

“All in all we can be very happy with what we have achieved, so that is why I was pretty happy after qualifying.”

There is the threat of rain for the race as the very periphery of Typhoon Fitow, that earlier in the week had threatened to severely disrupt the event, is now only likely to play a bit-part role.

Not that Vettel is concerned, adding: “It’s not a disaster if it starts to rain. We have rain tyres in the garage.

“They’re talking about heavy wind, but I think the typhoon has changed direction, so tomorrow should be fine in terms of conditions, whether it is dry or wet.

“If we get some of the rain from the typhoon, which isn’t 100 per cent clear at the moment, it doesn’t matter.

“The most important thing is we did the job in qualifying, and now we can look forward to the race.”

Hamilton, meanwhile, can now only hope he gets close enough to Vettel in the opening stages – which boasts two long straights – to give him a shot at an early attack and potential victory.

“I’m just going to be pushing as hard as I can to get past Sebastian and to put myself in the best position to fight,” the Briton said.

“I’m happy the car is as competitive as it is. The guys have done such a good job to put us up this high, but I think there’s more to come.”

Alonso knows he will need another storming first lap, as he has often produced this season, to give him a shot at hounding Vettel.

The Spaniard said: “The straights will be a big opportunity for us. Our start is normally good, although in turn one there is not enough space to really attack, so we will try in turns three and four where there has always been some action in previous years.”

With Webber down 10 places to 13th, McLaren's Jenson Button starts 11th, whilst Force India's Paul Di Resta lines up 15th.

Max Chilton was initially slowest, but, with Marussia team-mate Jules Bianchi handed a penalty for impeding Di Resta, the Briton moves up a place to 21st.