Christian Horner appreciates Red Bull still have a mountain to climb in their bid to catch Mercedes this season ahead of Formula One’s return to Austria this weekend.

Daniel Ricciardo’s maiden F1 victory in Canada owed as much to Mercedes showing they are far from bulletproof this year as to the Australian’s talent.

In taking the chequered flag in Montreal, Ricciardo ended Mercedes’ dominant run of six successive wins and five consecutive onetwos to haul himself up to third in the drivers’ standings.

Ricciardo, however, still trails championship leader Nico Rosberg by 61 points and second-placed Lewis Hamilton by 39, with Red Bull 119 adrift of Mercedes in the constructors’ table.

The win was welcome and unexpected, providing a huge tonic to the reigning four-times champions, but Horner knows Mercedes’ dominance will be difficult to completely break.

“If you think where we were three months ago it is an enormous effort by all the team in Milton Keynes and all the team in Viry (working for Renault ),” said Horner.

“Everybody did their bit to get us into a position to win a race and to get two cars on the podium (with Sebastian Vettel third in Canada).

“To get a double podium, to get that first win of the year, was a fantastic performance.

“But let’s not beat about the bush  – Mercedes were the quickest car, even though they ran into their issues. We still have a lot to do as we were 12 or 15 kilometres per hour slower on the straight compared to a Force India or Williams. That is where we need to improve.”

Even at this stage in the season, with 12 races remaining, it appears inconceivable anyone other than Rosberg or Hamilton will win the title.

Yet given the strides Red Bull have made, Horner feels his team can continue to push Mercedes.

“You guys (the media) asked at one point if Mercedes could win all the races, and I said theoretically they could but in all probability they wouldn’t,” he said.

“What we have managed to do is keep chipping away, to improve the car, the engine, and in Canada we were there to capitalise on some misfortune for Mercedes.”