Horner wary of 'challenging factor' that could derail Red Bull's Japanese GP

Christian Horner is wary of the "challenging factor" cooler track conditions can play in the Japanese Grand Prix after Red Bull's front-row lock-out.

The race has traditionally taken place in September or October in recent years, but has been shifted forward in the calendar to April - with cooler air temperatures as a result.

Teams were unable to complete their usual race pace simulations in Free Practice 2 after rain hit, but Red Bull entered qualifying as favourites, which was duly converted.

Max Verstappen pipped Sergio Perez to pole by just 0.066s, and Horner feels the race will be closer.

"I think we've understood the issues, but I think we saw that the race pace is more varied [heading into the race], and in these cooler conditions, how the tyres behave is going to be a challenging factor," he told Viaplay.

"But I am sure it is going to be an interesting race, and I am glad to be starting on the front row."

Red Bull head into the race having been defeated last time out in Australia where Carlos Sainz capitalised on a brake failure for Verstappen and floor damage for Perez to take the victory.

Despite being sure the team had solved the problems, Horner was felt the race could be close.

"It is Checo's best-ever qualifying here, so we're really pleased to have both cars on the front-row," Horner told Viaplay.

"It was another stunning lap by Max but I think the race could be a little closer tomorrow, but it is a great start to the weekend."