Haaland scored all three as Manchester City preserved their 100 per cent record at West Ham United, with Guardiola admitting surprise at his side’s early season performances.
The Norwegian has raced to seven league goals already this term as he hunts down a third golden boot since moving to England two years ago.
‘Erling is unstoppable,’ Guardiola said. ‘There is not a central defender, not even with a gun, who can stop him. We know how clinical he is. Everybody knows it.
‘He's playing much better in everything [this season]. The details, he stays 20 minutes or half an hour after training sessions now. Last season, not even once, he was there because he didn't feel good - tired, niggles.
Pep Guardiola says no defender in world football can thwart ‘unstoppable’ Erling Haaland
‘We are happy for another hat-trick, the quality of the finishing, but he was involved with the game today. He didn't lose one ball and he played unbelievable - not just with the ball but also defensively and offensively. He gave an extra pass. I'm really pleased for him.’
‘Only footballers know how important it is to have a break,’ Haaland said. ‘You need to calm your body and mind down because it's a long season.
‘It's not as easy as people think. I feel fresh and that's the most important thing. When you do that you can practice some things you want to get better at outside of training.
‘It's been a great start. Let's not get too far ahead because there are potentially 70 more games this season.’