Lewis Hamilton bemoaned Ferrari's "tricks" after Sebastian Vettel won the Belgian Grand Prix to close the gap on the championship leader to 17 points.
Vettel overtook polesitter Hamilton on a dramatic opening lap, which also saw Fernando Alonso, Nico Hulkenberg and Charles Leclerc involved in a huge crash at Turn 1.
The German found a way around the outside of his Mercedes rival onto the Kemmel Straight and Hamilton had no answer for the Ferrari's pace.
"Congrats to Seb. I did everything I could and we ultimately did well, but he drove past me like I was not there," said Hamilton.
"We have to keep pushing to see what we can do.
"They have got a few trick things going on in the car, I did what I could, we did what we could, so we have to keep working."
Vettel's win saw him surpass Alain Prost and climb to third in the list of most F1 race victories, behind only Michael Schumacher and Hamilton.
"I had a great start, I'm not sure Lewis saw me as he pushed me to the left in the first lap, but after last year I ended up short, and this year it was the other way around - this year was better," he added.
"As soon as I was ahead I relaxed. I had a good restart after the safety car [after the first-lap crash], and after that it was a very smooth race. We turned everything around and then controlled the race.
"Going through traffic, I was fortunate I didn't lose much time. Lewis wasn't really pushing anymore in the last 15 laps so I wasn't either.
"I enjoyed the race and to get so much time on this track is good and I always enjoy it in a fast car."
