Two-time champion Max Verstappen dominated both Friday practice sessions for Red Bull at the Spanish Grand Prix and then praised the changes made to create a faster and more flowing circuit.

Verstappent produced a 'double top' with fastest laps in both runs to finish quickest ahead of two-time champion and local hero Fernando Alonso of Aston Martin.

After a near-perfect day at the Circuit de Catalunya, where he claimed his maiden victory in 2016 and won last year, the 25-year-old Dutchman said the new layout was "more fun to drive" and would encourage overtaking.

"Overall, I think we had a very good day," said Verstappen, who leads this year's championship by 39 points ahead of Red Bull team-mate Sergio Perez.

"The car was in a good window and of course, you try to fine tune a few things here and there but on the short run and long run everything looked quite good.

"From my side, I felt very comfortable in the car looking after the tyres. I still need to look at the lap times of others but it was a good day."

Asked about the circuit, which has a revised final sector following the removal of a chicane to create faster and more flowing corners, he was enthusiastic.

"It's been much more fun to drive," he said.

"In general, F1 cars are better at high speeds so, for me, the last two corners are now much better to drive.

"I tried to follow a few cars, as well, and it seemed to be quite ok there as well -- so I was positively surprised for the overtaking."

His Red Bull team-mate Perez was fourth as he sought to shake off a "disastrous" weekend at the Monaco Grand Prix where he crashed in qualifying and failed to score a point