Mercedes director of trackside engineering Andrew Shovlin has highlighted the Spanish Grand Prix as the pivotal moment for the Silver Arrows' F1 turnaround.
The eight-time consecutive constructors' champions endured a torrid season, securing only one victory courtesy of George Russell at the São Paulo Grand Prix.
Porpoising affected some teams more than others as F1 ushered in a new technical regulation set for the campaign and with Mercedes suffering from the bouncing, it found itself fighting in the midfield as Red Bull and Ferrari battled for wins.
But developments helped the W13 become a clear-cut third-quickest car, before a final upgrade kit at the United States Grand Prix helped push towards the long-awaited victory.
Asked to pinpoint the pivotal moment for the turnaround in fortunes for the W13, Shovlin explained: "The one that will stick in the minds of the engineers is probably Barcelona.
"Barcelona was the one in which we made the biggest step in getting on top of the aero-bouncing phenomenon.
"We were able to have decent performance but it also allowed us to see there were other issues to solve with the ride of the car, it wasn't very good over the bumps, and it gave us the clarity to take those next steps.
"So whilst it was only a small step in the right direction, from a learning point of view, it was a really important update."