BAKU (REUTERS) - Red Bull's Sergio Perez set the pace in Azerbaijan Grand Prix practice on Friday with championship-leading team mate Max Verstappen close behind while Lewis Hamilton and Mercedes failed to make the top 10.

The Mexican driver lapped the Baku street circuit with a best time of one minute 42.115 seconds, 0.101 quicker than Verstappen.

"We've done very good progress, after Monaco we did a very deep analysis and today was like 'Wow, I finally understand a bit more this car, how I need to drive it," said Perez, who joined Red Bull this season.

"In all regards, I think this is the best Friday of the season, the most complete Friday in terms of data and how comfortable I feel with the car," added the man who has twice stood on the podium in Baku.

"I think we are definitely going to be in the mix."

Verstappen had been fastest in the first session with a time of 1:43.184.

The 23-year-old Dutch driver is four points clear of Hamilton, seizing the lead by winning in Monaco last month while Hamilton finished seventh.

"Performance-wise we had a great start to the weekend so far," he said.

"The car in FP1 (first practice) felt really decent and I was quite comfortable. Then for FP2 we made a few changes to see if it would be better but I think we went a bit backwards."

Seven times world champion Hamilton, Verstappen's closest rival after five races, was only 11th and more than a second off the pace as the once-dominant team struggled again.

His Finnish team mate Valtteri Bottas, the winner last time Azerbaijan hosted a race in 2019, was 16th and more than two seconds slower than Perez. He had been 10th in the first practice.

Hamilton said he had done all the laps required, without any mistakes, but the pace was missing as it had been two weeks ago in Monaco.

"We're definitely quite a chunk down and I think everyone will be scratching their heads and looking into the data trying to figure out how we can improve," he added.

"It didn't feel good in this session. I was pushing, I was on the limit but the car is limited. There's areas that it should be quicker but there's no more grip.

"It's not easy to be out of the top 10 in pace when we've had pace in other places but I don't really know why we're where we are."

Ferrari's Carlos Sainz was third in both sessions.

His team mate Charles Leclerc was second fastest in first practice and fourth in the afternoon, when he nosed into the barriers and smashed the front wing.

Ferrari still looked the team most likely to be challenging Red Bull for pole position on Saturday.

The "dirty" track proved slippery for drivers, who also had to contend with breezy conditions, as the sport returned to Baku without spectators due to the Covid-19 pandemic.

The weekend has been dominated by a row over "bendy" rear wings, with the governing FIA keeping a close eye on the situation before introducing new tests at the following French Grand Prix.