Saints went to Loftus Road just one place and one point better than Mark Hughes's bottom-of-the-table side, but the gulf in class on display was stark.
Saints boasted a deserved two-goal advantage at half-time courtesy of efforts from Rickie Lambert and man-of-the match Puncheon and, while Junior Hoilett reduced the deficit, Anton Ferdinand put into his own goal to secure a 3-1 win for the visitors.
Success was sweet for Puncheon having spent an unsuccessful loan spell with QPR last season, but he was more pleased that Southampton were able to show what he feels to be their true ability in west London.
"It's always good to get one against a former club, but the most important thing was getting three points," Puncheon said.
"We sort of got on the front foot and did what we've been doing in recent weeks
"I thought we were solid, and that showed in the first half and the second half.
"We have always known as a group that we shouldn't be where we are.
"There have been games that haven't gone our way and games that have slipped through our hands, but we were determined not to do that from back-to-front and in [terms of] finishing off goals and that happened."
QPR were poor for the most part at Loftus Road but Puncheon believes Southampton deserve credit for their performance.
"You can sit there and say it's easy, but we were on the top of our game on every yard of the pitch," he said.
"The two midfielders covered every blade of grass on the pitch, Gaston [Ramirez] and Rickie both put in a lot of work as did the full-backs, centre-halves and goalkeeper.
"That counts, that's what it's all about and that's what we did."
The result helps alleviate the pressure mounting on manager Nigel Adkins, whose future has come under increasing scrutiny in recent weeks.
Southampton have found themselves in the headlines for the wrong reasons as a result and Puncheon admits it has been hard to ignore.
"It's natural, we're human beings at the end of the day," he said.
"Just because we're professionals it doesn't mean that we don't see and hear things. We've got eyes and ears.
"That's part-and-parcel of football so you've got to take that on the chin and turn up on a Saturday."
After the game Adkins was full of praise for Puncheon, whose change in fortunes at Saints is remarkable.
The winger had looked certain to leave Southampton for pastures new earlier this year after a public falling out on Twitter with chairman Nicola Cortese.
However, the pair - rather surprisingly - patched things up and, having helped Saints secure automatic promotion from the Championship, Puncheon is thriving in the top flight.
"I thought he had another excellent performance," Adkins said.
"He probably had a more consistent, complete game over the 90 minutes. He has done it in flashes.
"He has had a great pre-season and he has worked really hard. His attitude has been top draw and his performances has backed that up.
"He wants to have a go. Sometimes he has been in, sometimes he has been out. He could have scored more goals as he put several good shots in."