Captain Graeme Smith told reporters his side had been "stressed" despite going into the game as the world's number one-ranked team.
"Every time you come to the (Asian) sub-continent you always have a degree of stress," Smith told a news conference.
"Pakistan have played well in these conditions of late, I have to say that they have outplayed us, so it's very disappointing.
"Every time you come to the (Asian) sub-continent you always have a degree of stress," Smith told a news conference.
"Pakistan have played well in these conditions of late, I have to say that they have outplayed us, so it's very disappointing.