A complete search of the internet has found these results:
in the first row is the most popular phrase on the web.
"in the first row" usually refers to a person (or animal/object) sitting in the first row in front of a stage or other central area. "at the first row" could be used in a different context or to describe where someone is standing.
3,800,388 results on the web
All those in the first row come from the media.
Your honor, this man in the first row is a reporter and he's giving questions to counsel.
We saved you a place in the first row.
There's one in the first row.
In Table 2, the heading in the first row of the third column is replaced by:
In food category 220.127.116.11 'Dietary foods for babies and young children for special medical purposes as defined in Directive 1999/21/EC', the text in the first row is replaced by the following:
My mother was in the first row of the women and she signalled to us with her eyes.
Why is Roberto in the first row? Is he a VIP?
Drivers in the first row signifying that they're ready to race.
I can't believe we had to sit in the first row.
400,300 results on the web
Standing at the first row, you can see the entire field, including the bases.
"Hey. Bill! Where are you? I'm standing at the first row next to the hot-dog stand."
She left her cart at the first row in the department store, but she can't find it now.
Where is the cheese? It's piled at the first row on your left, next to the milk.
Are you guys going to be at the first row of the concert when I arrive?
I want to sit in the third row, but we could meet at the first row.
At the first row on your right, you will see that we have a brand new shipment of products being shelved.