George Russell says his Mercedes Formula 1 team is "the most confident we have been" in three years over its recent on-track performance.
Russell and team-mate Lewis Hamilton locked out the second row in Spain, two weeks after Russell clinched his second career pole and the squad's first podium of the season in Canada.
Hamilton qualified three tenths behind polesitter Lando Norris and world champion Max Verstappen to claim third, with Russell just 0.002s in arrears.
Mercedes endured a third consecutive troublesome start to the season since the 2022 ground-effect regulations came into force.
The team has had many ups and down over the past 24 months, with several false dawns along the way.
But with the team now confirming its progress across wildly different circuit types, Russell said it is now the most confident it has been since the 2022 rules reset over its form curve.
When asked if Mercedes' performance in F1's Barcelona proving ground has eliminated fears that its latest progress could be another mirage, Russell said: "Well, you never know 100%.
"But this is for sure is the most confident we have been over the last three years of what we've brought to the car.
"This is natural as well, we're all gaining experience, we're all three years into these regulations.
"And I think we all know what makes a good race car in this sort of era. I think it's proven how tight it is out there with the top four teams at the moment.
"Probably in the coming races, marginal differences will make a big difference in terms of your grid position, but that's what Formula 1 should be about."
Mercedes' fortunes have been transformed by a series of incremental upgrades since Miami, with an all-new front wing concept seen as one of the centrepieces.
But it has also chased performance from the floor, bringing a lighter version of its latest design to Spain.
Helping speed up its upwards trajectory, Mercedes' major Miami package was actually planned for the following round in Imola, while its new front wing was brought forward from Canada to Monaco, even if there was only one example available that Russell ran.
With the tightening grid making every one-hundredth of a second potentially decisive, as proven in the most recent qualifying sessions in Montreal and Barcelona, Russell praised the staff at Brackley for its efforts in fast-tracking those parts out to the W15.
"I'm standing here with a lot of pride of what the team achieved," he added.
"There has been a hell of a lot of work to bring this turnaround and bring these upgrades consistently a race or two early than they were planned.
"We've been to three circuits now [with the upgrades]. In Monaco, we were 20 milliseconds from qualifying third, and it would have been a podium.
"Canada was obviously great and here we are on the second row, and there's going to be a good fight with Lando and Max and I think we'll probably just have the edge on Ferrari."
