Toto describes the team's first 1-2 finish of the season at the Spanish Grand Prix as a relief but stresses we must stay calm and humble.
'We will savour the result'
Lewis powered to a spectacular victory at the Circuit de Barcelona-Catalunya, leading home Valtteri to lock out the top two steps on the podium.
Nerves and tension changed to euphoric celebration as the chequered flag fell, but Toto admits we must keep our feet on the ground - because the pecking order changes from track to track.
"That was a great result but there was no point where it felt as comfortable as it might have looked from outside," he explained.
"It feels like a long time since we had a 1-2 finish, so there's definitely a measure of relief in how we asserted ourselves.
"But we know as well that this was a good circuit for us and the temperatures fell in our favour as well.
"So, we need to stay calm and humble, because it can be a different ball game again next time round.
"We will savour the result this evening (Sunday) - but our thoughts are already turning to Monaco, to the struggles we had there last year and to how we can make sure not to suffer a repeat."
'Our hearts were in our mouths'
A strong opening stint propelled Lewis into a comfortable advantage and he was able to manage the race from there, taking a commanding win.
Valtteri fell behind Sebastian Vettel at the start but jumped to P2 after Ferrari opted to pit under the Virtual Safety Car. Valtteri didn't and while such a long stint on Mediums was a risk, it paid off.
"Lewis did a fantastic job: a great start, impressive pace in the opening stint and perfect management of the Medium tyre," Toto said.
"For Valtteri, we tried to overcut in the first stint and just missed out on passing Vettel. Then when Sebastian took the chance to pit again under the VSC, we decided to do the opposite and take the Medium tyre to the finish.
"That involved running the tyre a long way, a little bit into the unknown with over 45 laps to do on it, and we had our hearts in our mouths in the final laps as there were some vibrations on the front axle as well.
"Valtteri did the perfect job to manage the load on the left front and the falling tyre temperatures on old tyres, and sealed a really special 1-2 finish."