Westley endured a troubled time after taking over at Deepdale last season but saw North End make the perfect start to the new campaign when Jack King headed home on 29 minutes.
Nicky Wroe, a summer signing from Shrewsbury, then doubled the lead five minutes before the break to help the League One side into the next round.
And after fielding a starting 11 which featured ten summer signings, Westley insisted he finally had a dressing room capable of delivering success.
"It was a good way for the new squad to start. They're good men, they're good people, they're good footballers, they're intelligent and they've only had six weeks to come together, which is not a long time," he said.
"It's been a difficult pre-season for us and we've worked very hard - we're going to get much better over the coming weeks, but on the whole it would be stupid to ignore the positivity of what they've done.
"As a football manager and a football player you go about your work and you hope by doing your work you can give the club some pride."
Simon Grayson's side launch their Championship campaign against Cardiff on Friday night and the Terriers boss admitted some players would pay for the defeat with their places.
"I'm disappointed with a few players' performances and we didn't perform as a team," he said.
"We warned the players about what Preston would be like. They'd get in your faces, make it difficult for you, they'd leave their foot in, their elbows in, and they'll work you, and we didn't handle it
"It's frustrating for me, but it will be frustrating for the players when I pick the team on Friday and one or two are not in it.
"Everybody had an opportunity tonight to stake a place for Friday night and some of them have not taken those opportunities."