Mercedes team boss Toto Wolff says he was unsurprised by the strong pace of the Ferrari around the Spa-Francorchamps circuit.
'Everybody is extracting maximum out of the car'
After claiming a 1-2 at the super-fast Silverstone, Mercedes had been expected to dominate the Belgian Grand Prix at the similar Circuit de Spa-Francorchamps.
But it was far from a simple stroll in the Ardennes forest, with Ferrari's Sebastian Vettel chasing Lewis Hamilton right to the chequered flag.
"It's really difficult to attribute patterns of circuits to specific cars and we have seen this," said Toto. "You think you are good and then you are not as good or the opposite.
"What we have seen is that we weren't great on the high downforce slow races such as Hungary and Monaco. We need to improve that for Singapore. It's a tough, tight fight with Ferrari. Everybody is extracting maximum out of the car.
'It was not a critical blister'
"In this development race we need to bring performance to the car every race in order to have our nose in front. That's why I'm not surprised that they were good at Spa."
The Ferrari threat appeared more apparent in the final stint, as focus shifted onto tyre strategy. While the two red cars swapped onto a new set of the UltraSoft tyres, Lewis and team-mate Valtteri Bottas opted for the harder-compound Softs.
"I think it would have been a less comfortable race without the Safety Car because we needed to decide whether to pit Lewis with the blister on the rear tyre," Toto explained. "It was not a critical blister - but there were 14 laps left and it would have put us and Lewis in a very difficult situation. As annoying as the Safety Car looked for us it was actually optimum for us at that stage of the race for Lewis.
"We had no new UltraSoft sets left because we used it in qualifying as an advantage. We expected the Soft to be the faster tyre for the last 12-14 laps depending on how long the Safety Car would have stayed out.
'That proved to be the right decision'
"The UltraSoft was clearly a good option for the first two laps of attack after the re-start but then not the right one. There were a lot of discussions about it whether it was the right decision. It proved to be the right thing"
"As the leading car, you can only lose. You either lose track position by pitting, going onto a new tyre and then not recovering or you keep your car out and then you are under attack.
"I think what made the difference was that we weren't quite sure if we had a blister on Lewis' right rear tyre. We couldn't identify whether it was pickup or a blister and that was the argument in favour for pitting for new tyres."
"We opted for a setup that would be the quicker race setup but sacrificed downforce for qualifying. We left lap time on the table in the second sector in order to have the quicker car in sector one and three. That proved to be the right decision. Ferrari had more downforce on the car and all the deployment modes that we had in our back pack made Lewis stay in front."