After late victories against Huddersfield Town and Southampton, Silva scored with seven minutes left on the clock for a City side who, in cantering to an eight-point lead, are showing all the hallmarks of champions-elect.
For large periods on Sunday, however, City were frustrated by an organised West Ham but their sheer will to win proved too much for the Hammers as Guardiola's side restored their comfortable lead ahead of next weekend's Manchester derby.
"It's a big victory," Guardiola told the BBC. "It showed what we are.
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"It was similar to the last few games, in the second half I thought we would score. It was massive. They played 10 players inside the box, it was almost impossible.
"We started really well but we lost our patience. We didn't have any rhythm because (West Ham goalkeeper) Adrian was taking 30 seconds every time.
"But you have ups and downs -- what is important is that in the second half it was outstanding the way we played. It means we have done 39 points in a row. That is a lot. You see how they run and how they fight, that's why we are so proud again."
Guardiola has favoured a lone striker this season, with either Sergio Aguero or Gabriel Jesus deployed at the head of their fluid, interchangeable attacking system.
But City played both in the second half on Sunday as they laid siege to Adrian's goal and Guardiola said the performance of the Argentine and Brazilian in tandem had given him plenty to consider.
"You have to try to solve it (when teams pack the defence). We had two strikers in the second half and that helped, it was a big lesson for me. We created more with two," he said.
"The pace was better, we had more presence in the box. Kevin de Bruyne playing as the holding midfielder gave us the tempo. We were much, much better."
City have been in irresistible form this season but it appears that teams may have identified a potential Achilles heel in their defence at set pieces.
Angelo Ogbonna's opener for West Ham came directly from a corner, as did the goal that City conceded against Huddersfield last week, while Southampton troubled them from set pieces during the week.
Against an imposing United lineup that includes Romelu Lukaku and Nemanja Matic, the leaders could have their work cut out next week against master-tactician Jose Mourinho.
"We spoke a lot about defending set pieces but they are taller," Guardiola added. "It will happen again next week against United so we have to try and concede fewer set pieces."
(Reporting by Tom Hayward in London; editing by Clare Fallon)
