May I offer you a quote from The Official Driver's Handbook for Ontario for everyone's edification:
Yielding the right-of-way
"There are times when you must yield the right-of-way. This means you must let another person go first. Here are some rules about when you must yield the right-of-way.
"At an intersection with stop signs at all corners, you must yield the right-of-way to the first vehicle to come to a complete stop. If two vehicles stop at the same time, the vehicle on the left must yield to the vehicle on the right."
Why this little lecture? Well, on my way home from work last night, I approached the intersection of Bay and Gloucester, two one-way streets. Refer to the picture: I was the red car and some @$$hole was the blue car. Well, we both approached the intersection at exactly the same time and both came to a stop. Armed with my knowledge of the Ontario Traffic Act, I then proceeded to enter the intersection. So did Mr. @. Since I was farther into the intersection than he was, I had to take some evasive manoeuvres to avoid a collision, while Mr. @. was honking at me like I was the idiot who didn't know how to drive. Good thing he didn't run into me or who knows what would have happened.