In F1 even a minimal time gap can mount up on the racetrack, but 0.093s is the blink of an eye. Third quickest was Carlos Sainz making his debut in the Ferrari, followed by Kimi Raikkonen in the Ferrari-powered Alf Romeo.
Next quickest was defending world champion and hot favourite for 2021 Lewis Hamilton in the Mercedes, who uncharacteristically had a spin on day one and again on day three.
Notwithstanding setting the quickest time, Verstappen is adamant Mercedes remain the favourites, even though Hamilton and his teammate Valtteri Bottas had problems throughout the three-day test.
"I don't think we are the favourites," Verstappen said after day one. "If Mercedes wins that many championships in a row, I think it's still the same as before we came to the test."
But Andrew Shovlin, the Mercedes team engineering director, claims the data they have gathered after three days suggests Red Bull is quicker than the Mercedes.
"We've made a bit of progress with the balance on higher fuel and the car was more predictable, but we can see from the data we've collected over the last few days that on race pace we're not as quick as Red Bull."
Mercedes team boss Toto Wolff admits he is worried, given they only have 10 days before the season begins in Bahrain.
"I always worry, sometimes for the right reasons, sometimes for the wrong reasons," he said. "Pre-season testing is always exciting because you always find the hair in the soup, things that are not good, and we had quite some struggles in the first two days."
Bottas described his test sessions as "definitely the most challenging start", dealing with a gearshift problem.
"Time is even more limited nowadays, so definitely not ideal. Only one and a half days as a driver and for me day one was compromised. But at least I feel the recovery has been pretty good in the last two days. Overall, the feeling is not bad."
Hamilton by contrast seems to be "excited" and revelling in the fact that he may have some rivals this year.
"Without doubt, it's quite impressive to see the speed of some of the other teams," Hamilton commented in a press conference following testing.
"I think Red Bull are looking particularly strong. And it's great to see McLaren are also looking strong, also Renault [meaning Alpine]. I'm so excited because that means more fun."
Hamilton did not include Alpha Tauri as being amongst the teams that impressed him even though Tsunoda and teammate Pierre Gasly were second and 11th quickest overall.
Gasly in his second season with the team following his demotion from the Red Bull sister team in 2019, is optimistic about the new car.
"So far we're really happy, it's a step forward compared to last year," he said, even though last year he won the Italian GP at Monza.
"Reliability has been perfect all three days so far so really positive on this side. We saw Mercedes they have a strong engine. They showed it with McLaren and Williams, you can see they have a lot of potential", which is rather an understatement, given Mercedes have dominated for seven seasons!
McLaren team principal Andreas Seidl is not getting carried away with his team's prospects, even though Daniel Ricciardo was seventh quickest overall.
"The team both here in Bahrain and back at the factory has done an excellent job alongside our Mercedes colleagues to deliver a reliable car, which is crucial to a productive test," Seidl said.
"Once again, the competition is looking very tight between the teams. The stability of the regulations makes it likely that we're in for another close season of Formula 1, with plenty of battles ahead."
Last year's championship though, was anything but close, with Mercedes and Hamilton in particular literally driving away with both championships.
Alpine's new racing director Davide Brivio, who replaced Cyril Abitetoul following the latter's surprising departure from the team, believes McLaren and Red Bull are in good shape and says of his own team that they are "here to improve and give our best. The goal is to improve more and more, that's why we are here."
Brivio comes to F1 as the former Suzuki MotoGP boss, but will not be the Alpine team principal as such, according to executive director Marcin Budkowski.
"Brivio will be in charge of the drivers and of the activities on the track," Budkowski noted.
When asked, given his inexperience in F1, what he would bring to the team, Brivio said: "Maybe the experience from a human point of view, how to handle a team, how to motivate the people and setting goals."
Budkowski says he doesn't think there will be a clear-cut midfield pack, when asked who Alpine's closest rivals might be.
"Honestly, I don't know," he said. "It's tricky. It's a tough one to call, really. I think it's not a midfield anymore, it's a field really. I mean we still expect Mercedes at the front - they had a few issues and they're probably sandbagging a little bit at the beginning of the test - we still expect Red Bull to be strong.
"But behind that, it's a field really. Where we are in that field is difficult to say, I expect it to be competitive."
There was a question mark over the participation of Fernando Alonso for Alpine in the test, given a few weeks ago he broke his jaw after being hit by a car near Lake Como when out on a cycling training ride.
He has two titanium plates in his upper jaw and there was a concern that he might not be comfortable wearing a helmet, together with the G-forces drivers have to endure. But Alonso completed 206 laps and Budkowski says there were "no sequels from his accident. He's in top form.
"He was in the car, straightaway quick, reliable, giving amazing feedback to the engineers. That's what you expect from Fernando."
George Russell, driving the Williams, was sixth quickest in testing, yet he claims none of their data suggests they have closed the gap to the midfield pack. He believes it will be a yo-yo season for Williams, who may get faster at some events and slower at others. Russell was impressed with the performance of Kimi Raikkonen in the Alfa Romeo, though.
"Kimi is looking very, very fast, no doubt, and the midfield guys are looking fast as well, so yeah, we'll have to wait and see."
Sebastian Vettel was looking forward to testing the Aston Martin, which looks great, but didn't go as well as it looked. He said it was "not exactly the week we were hoping for", with a gearshift problem and he only completed 117 laps, compared to Gasly who did the most, with 237 laps.
While the drivers were testing, F1 lost an icon, with the death of former F1 commentator Murray Walker MBE, who covered the sport for 24 years. Walker, who was 97, was a British Racing Drivers Club Associate member and the BRDC led the tributes.
"A friend, a true motorsport legend, the nation's favourite commentator and a contagious smile. Murray will be sadly missed; his mark and his voice will live on in motorsport and our hearts forever."
Walker was self-effacing in admitting he got things wrong, and his autobiography was called Unless I'm very Much Mistaken after he once famously said "unless I'm very much mistaken - which I am."
His comments were called "Murrayisms" and there were some classics:
"With half the race gone, there is still half of the race to go."
"Anything happens in Grand Prix racing, and it usually does."
"Schumacher wouldn't let him past voluntarily. Of course, he did it voluntarily, but he had to do it."
RIP Murray Walker and thanks for the memories, bloopers and all.