However, Pakistan turned the tables on England, the world's top-ranked one-day international side, with a 14-run victory at Trent Bridge to get their World Cup campaign back on track.
"We had an upset against the West Indies on Friday but, yes, the guys bounced back very well," fast bowler Hasan told reporters.
"We do a lot of hard work and we believe in ourselves and we have faith we can win the World Cup. People are saying we are unpredictable, but we don't like it."
After the humbling against West Indies, Pakistan's batsmen went on the offensive against England, mustering 348-8 after being put in to bat first.
"We were very disappointed we lost 11 ODI games in a row but one thing is very important, we believed in ourselves," Hasan said. "We needed just a little bit of a kick, and we got the kick. We are very confident, our team is very good and balanced.
"After the first match we sat down and talked about our weaknesses and about our plans and execution, all these things. One thing is very important, our coach (Mickey Arthur) is always backing us."
Man-of-the-match Mohammad Hafeez, who top-scored for Pakistan with an 84 off 62 balls and also took the wicket of England captain Eoin Morgan, said Pakistan were desperate to turn things around.
"It's a feeling of total relief. After the game against the West Indies we were really looking forward to this match and putting things right," he said.
"We know this team is very capable we just needed to start converting some matches into wins."
(Reporting by Sudipto Ganguly in Mumbai; editing by Peter Rutherford)
