"The more the merrier" was how Lewis Hamilton described Red Bull's resurgence at a hot Hungaroring on Friday, adding the Budapest track "might be his favourite".
As expected, Mercedes were once again the fastest car on Friday practice with reigning World Champion Hamilton taking P1 in both sessions.
However, while his team-mate Nico Rosberg was P2 in the morning, the German slipped to fourth place in the afternoon as the Red Bull pair of Daniil Kvyat and Daniel Ricciardo were both ahead of him.
Asked about Red Bull's challenge, Hamilton replied: "That’s good, that’s good. The more the merrier, the more battles we have the better. The car is feeling quite good this weekend."
Temperatures were quite high on Friday with the track reaching in excess of 50 degrees Celsius late in the afternoon and, although he admits it is difficult to drive in those conditions, Hamilton is quite pleased with his efforts at the Hungaroring.
"It was really good fun out there today. I'm starting to think this might be my favourite track," the Brit, who has won the Hungarian GP four times, said. "It's so fun to drive with the combination of corners and undulations. The way it all flows together just feels old school.
"It's incredibly hot, though – like driving in a sauna. You're drenched in sweat before you even get in the car with all the thermals on and I lost about half a kilo just in that session.
"It's a big challenge to get a good lap here in these conditions and I think everyone has struggled a bit.
"It's meant to be a bit cooler on Sunday which will be easier to cope with physically but will obviously change the balance a bit, so it should be interesting.
"Our car feels strong here though and I'm very happy with it so far."