Arteta made the declaration after their semifinal defeat at PSG this week.
The former PSG midfielder's claims were rejected by opposing coach Luis Enrique and many pundits watching on.
But on Friday, ahead of their trip to Liverpool on Sunday, Arteta insisted: “I stand by what I said, 100 per cent. I’ve watched it back, seen all the stats.
“When you look at all the important stats, the ones that give you the best platform to win football matches, it’s crystal clear who was better.
“With an expected goals of five against three, which we had over the two legs, normally you’re in the final.”
"We were the better team!"
Arteta also said: “If you face PSG and they blow you away, you shake hands and say, ‘We’re not ready still’.
“When you look them in the eye, suffocate them in the way we did there, you were the better team.
“But it’s not about the winning probability, it’s actually making it count.”