American midfielder Silva scored three goals in a first-half blitz to help DC United to a come-from-behind win against the Impact at the Stade Saputo.
DC United (25 points), who have played an extra game, are now two points clear at the summit after 15 rounds following New England Revolution's (23 points) loss to New York Red Bulls on Sunday.
As for Montreal, they remain rooted to the foot of the table with 10 points, though they have only played 13 games.
Silva had given DC United a sixth-minute lead before two quick-fire goals from Jack McInerney and Andres Romero had Montreal 2-1 up after 21 minutes.
Nicholas DeLeon restored parity two minutes later and that is when Silva took centre stage, scoring in the 39th minute and then converting a penalty in the fifth minute of first-half injury time to put the game beyond doubt.
Silva had previously gone nine games without a goal before finding the back on three occasions in Montreal.
"We had high expectations coming into the season," Silva told MLSsoccer.com.
"To be in first place is a blessing, I think. Obviously, everybody is excited -- especially after last year, when we were in last place.
"There were times last year when you'd walk into the locker room and you could just see the guys were down."
Meanwhile, nine-man Dallas surrendered a two-goal lead as they drew 2-2 at the Portland Timbers in their Western Conference clash.
Dallas had a two-goal lead at half-time thanks to Fabian Castillo and Blas Perez.
Will Johnson pulled a goal back for Portland from the penalty spot with 11 minutes remaining and that sparked an astonishing turn of events at Providence Park.
Dallas pair Moises Hernandez and goalscorer Perez were both sent off during the final five minutes, paving the way for Portland to score an unlikely equaliser courtesy of defender Pa Kah.
