Lewis Hamilton eventually won the Grand Prix by a margin of over 20 seconds, highlighting the gulf between the two drivers this weekend.
"You look back and you understand what is missing in the preparation to the race, or this race, or the next races".
"It's nearly all sorted", Mercedes boss Toto Wolff confirmed in the wake of Hamilton's victory in the Spanish GP. "Let's keep this up".
In the Drivers' Championship, Hamilton now enjoys a substantial lead over second-placed Vettel, with the Briton sitting on 95 points versus the German's 78.
Defending champion Hamilton has had to be patient this season, waiting until the fourth race in Azerbaijan to register his first victory of the campaign.
Out of the cockpit, he continued the theme, adding: "Today I felt a synergy with the vehicle that I hadn't been feeling all year". "It's a really good feeling".
"I think you can only really take it one race at a time", he explained. "It's hard to beat all of these records that he has".
Daniel Ricciardo was a low-key fifth and spun under the controlled speed of the VSC, although rallied thereafter to set a succession of track lap records late.
The man with more pole positions than any other driver in the history of Formula One, his tally now standing at 74, had been going through a drought since Australia in March. Mercedes and Hamilton's return to form means the reigning champions are "back in business" for 2018, says Sky Sports, but can they they win in Monaco?
Australian Daniel Ricciardo was fifth in his Red Bull when the virtual safety auto was called out on lap 41.More news: Here's the approximate timing of the severe thunderstorms forecast for Tuesday
Hamilton led into Turn 1 as Vettel passed Bottas for second.
"We went to Melbourne, the auto performed well, he was in the lead, solid, and then suddenly he found himself behind a Ferrari and couldn't overtake".
After making an early pit stop on lap 19, Bottas then had to make a set of medium compound tyres last 47 laps in order to complete an unlikely one-stop strategy.
"We were not quick enough", Vettel accepted.
"I think for the team, I think it has been a struggle", Hamilton said after qualifying.
Hamilton will hope also that Ferrari fail to repeat the form that brought them a one-two finish in the Mediterranean principality past year where Vettel won. He made the right strategy call by pitting when the virtual safety vehicle was deployed but ran over front wing debris from Verstappen's auto that caused some damage.
"I am going to sleep like a baby tonight because I know I did my job this weekend to the maximum and I did not leave anything on the table".
"We couldn't make the tires last", said Vettel. Esteban Ocon faced technical issues of his own 15 laps later, forcing him to park his smoking Force India by the side of the track.