Max Verstappen goes quickest in both practice sessions in Barcelona ahead of the Spanish Grand Prix

Red Bull have continued to assert their authority on the current F1 season by dominating the first two practice sessions at the Spanish Grand Prix, but it was a day for major experimentation.

After setting the pace in the first practice session, world champion Max Verstappen also went quickest in second practice.

However, these really were true definitions of practice sessions with many teams testing out upgrades to their cars on a new version of the track in Barcelona.

Having had a tricky chicane since 2007, the circuit has returned to two fast right-handers towards the end of the lap, which were previously in action between 1991 and 2006.

In terms of upgrades, Aston Martin’s Fernando Alonso tested out revisions on his front and rear wings, while the Ferraris have a revised sidepod and floor edge.

In fact, the first session saw Ferrari’s Carlos Sainz drive with the upgrade, while Charles Leclerc continued with the standard specification so they could compare the two. They both ran with the upgrade in P2.

First practice saw Verstappen a massive 0.768 seconds quicker than his team-mate Sergio Perez, while Alpine’s Esteban Ocon was third and Nyck de Vries of Alpha Tauri fourth.

With drivers slightly more accustomed to the adjustments of their car, as well as the track, the second session provided much closer times.

It was Alonso who came closest to toppling Verstappen’s time, finishing just 0.170 seconds behind the Championship leader.

Sitting pretty at the top of the tree, Verstappen had time to reflect on the changes made to the track.

“It’s been a lot more fun to drive,” he told Sky Sports F1.

“F1 cars in general, they feel better at high speed, so, for me, the last two corners are much better to drive.”

“I tried to follow a few cars as well and it seemed actually quite okay through there as well so I was positively surprised for the overtaking,” Verstappen said.

Nico Hulkenberg’s Haas was third quickest in second practice, while Perez was fourth and Ocon came fifth.

George Russell was the best placed Brit in eighth spot and his Mercedes team-mate Lewis Hamilton posted the eleventh quickest time.

Speaking after second practice, Hamilton said: “It was a difficult day one.”

Upgrades to the Mercedes cars – including a new floor, sidepods and suspension – were first trialled in Monaco.

“It’s so different from last week, of course,” Hamilton said.

“We’ve just got to work on trying to figure out how we can extract more on the single lap.”

Looking ahead to the weekend, Hamilton added: “It’s a struggle for me currently to get into the top 10.”

The race weekend continues with third practice and qualifying on Saturday, before Sunday’s Grand Prix.

Verstappen has a 39-point lead at the top of the drivers’ championship, with his Red Bull team-mate Perez his nearest contender.