It would have been stupid for NP to try to defend and risk what is his only good finish this season. Prior to the race nobody would have bet a dime on him finishing in the points. So, of course he let the faster LH by.
As far as Massa goes, MS said after the race that he had serious trouble with brakes and tyres, which is why he couldn't even remotely keep up with LH's pace. MS said something to the extent that LH would have probably gone around the outside just as well.
That said, LH did show some remarkable pace this race, although fastest lap goes to Heidfeld. Hamilton obviously was the only one who was consistently fast over all stints.