Vettel has consistency on his side, with the German finishing all but three of his 12 races so far on the podium while Hamilton has been out of the top three in five grands prix, and a team mate playing a supporting role.
"He was probably waiting for me to make a mistake".
"I think first of all it's hard to attribute patterns of circuits to specific cars", Wolff said. "I'm not entirely happy".
The safety auto was deployed on the 30th of 44 laps and stayed out for four while marshals cleared up debris from a collision between Force India's Sergio Perez and Frenchman Esteban Ocon.
"Initially it felt like that's a mistake, but in actual fact it was actually a really good thing, because if I came out of the last corner with that gap, he would have had the momentum, being three or four vehicle lengths behind, to really propel and really get a good tow, and come and slip past me".
Hamilton took his fifth win with championship points leader Vettel second, 2.3sec behind.
Four-time champion Vettel came home second ahead of Australian Daniel Ricciardo of Red Bull, Finn Kimi Raikkonen in the second Ferrari and his compatriot Valtteri Bottas in the second Mercedes.
"We need to go race by race and every race there are different situations".
Hamilton made a good start to the race on the long climb up to Eau Rouge, but Max Verstappen's hopes ended on lap 8 when his Red Bull lost power. "But this is not a topic we want to tackle now, or over the remaining races of the season. I don't know what to say - it's just a very tough year". The Mexican couldn't avoid his team mate and his auto sustained heavy damage, while Ocon recovered thanks to the race stoppage to finish in sixth place.
Their tense relationship is degrading fast.
Hamilton argued that the safety auto was deployed even though there was no debris visible on the track, but his boss Wolff gave FIA officials the benefit of the doubt.
After bumping on the track at the Azerbaijan GP in June, they did it again when they touched wheels as Ocon moved on the outside of the track shortly after the start, with Perez responding by squeezing the Frenchman against the barrier.
Debris from his car's broken front wing littered the track while Perez's right rear tyre was punctured, leaving him limping back to the pits on a rim. "He risked my life", said a furious Ocon.
After both cars pitted for repairs, Ocon finished ninth but Perez had to retire just before the end.
Drivers worry that their tires lose heat if they stay behind the vehicle too long. "I was too close at the restart".