Sporting Kansas City moved into first place in the Eastern Conference with a routine victory over lowly Toronto FC.
It took Sporting 21 minutes to find the opening goal as Saad sent a blistering strike towards goal from outside the box that beat TFC goalkeeper Joe Bendik to his right.
In the second half, Saad completed his brace as he banged home a rebound left by Bendik from a thumping Kei Kamara shot.
The Reds made matters worse for themselves as they were forced to play with a man down after Reggie Lambe was sent off for a violent tackle in the 56th minute.
Toronto had yet to lose a game by more than two goals this season, but Bieler made it 3-0 off an easy tap in following silky buildup play.
With the Impact losing 4-0 to the New York Red Bulls, the win against Toronto puts Kansas City into sole possession of first place in the Eastern conference with 33 points from 20 games played.