It was an outing to forget for hosts England, who were dismantled by nine wickets at Old Trafford.
England struggled to 135-7, a total chased town by Pakistan inside 15 overs with just one wicket lost thanks to Sharjeel Khan (59) and Khalid Latif (59 not out), who shared a 107-run opening stand.
"The game was all about momentum. The way we were going allowed Pakistan to get on top," Bayliss told Sky Sports, having watched his side lose 54-6 during their innings.
"We didn't show urgency with our running. We played like pretty boys at one stage.