Put in to bat, Pakistan rode on a century by opener Fakhar Zaman to post a massive total of 338/4 in the allotted 50 overs.
Amir picked up three wickets for 16 runs from his six overs.
Fakhar brought up his maiden century in his fourth one-day global by muscling a sweep of Ashwin for his 12th boundary.
The left-arm pacer extracted movement both in the air and off the pitch and quite a few of his deliveries were nearly unplayable.
Thank the cricket gods that Azhar Ali dropped Virat Kohli at slip in the third over, before Kohli was caught the very next ball. The likes of Yuvraj Singh, MS Dhoni and Kedar Jadhav were at least expected to lead some kind of a fightback and offer India some sort of respectability.
# Ravindra Jadeja took a brilliant catch running backwards to get rid of the left-handed opener.
By the time Pandya was run out in the 27th over following a awful mix-up, the match was as good as done and dusted.
Earlier, Indian skipper Virat Kohli won the toss and as expected chose to bowl first in Champions Trophy final against Pakistan, here at The Oval.
Fakhar, the man-of-the-match, shared an opening stand of 128 with Azhar Ali (59).
Pakistan openers continue to trouble India with timely big shots. The Pakistan players ran around the field and fireworks were set off around the ground. They played with courage and belief. Pakistani shoulders slumped but India's captain lasted only one more ball, closing the face of the bat early as the edge was grabbed at point. Kohli's bowlers panicked and the fielders were awful.
Bumrah's first three overs cost 24 runs, including four wides. But the more consistent you get in learning from games like this, it s better for the team in the future.
But the umpires checked for a no-ball and replays showed Bumrah had over-stepped.
Incoming batsman Babar Azam kept on supporting the 27-year-old in-form batsman by giving him the strike. Zaman had been similarly reprieved in the morning, when he was caught off a no-ball for three.
Pakistan were 227 for the loss of two wickets after 37 overs. Embraced aggression, freedom in play.
# Virat Kohli (5) was the second Indian batsman to be dismissed.
"Congratulations to Team Pakistan on their great performance in winning #CT17 And how wonderful to watch Fakhar's raw talent in action", Pakistan cricket great Imran Khan tweeted.
# Shadab Khan became the youngest player to feature in an ICC ODI final, beating Yuvraj Singh's record of 18year 308days in 2000 (Shadab 18years 257days). He slogged the next ball over the deep extra cover boundary, and the next ball over the long on boundary.
He got a few streaky boundaries upfront but then settled in to give each Indian bowler, a mighty thwack.
But at 200 for two, Pakistan were well-placed for a big score, with Hafeez bringing up the 300 when he pulled the generally admirable Kumar for six.