Sam Allardyce: "It was a fantastic victory for us, a really pleasing one for us all and one I think in the end, we deserved.
"It's our first back-to-back wins.
"We finished 10th in the Premier League last year and only won three games away from home.
"We have already won two now - we have won at Blackpool and we have won here - it's our first back-to-back wins of the season, which is far quicker than we did last season, so it shows we are progressing."
Rovers took the lead with just three minutes gone when Pedersen took advantage of a rare slip by Cheik Tiote to fire past Tim Krul.
It took Newcastle until two minutes after the break to get themselves back on terms when Andy Carroll climbed superbly at the far post to power his seventh goal of the season past Paul Robinson.
However, with eight minutes remaining, they were caught by a sucker punch when substitute Roberts tussled with Mike Williamson under Robinson's long clearance and, after running on to the loose ball, slipped a shot past the advancing Krul to clinch victory.
Magpies boss Chris Hughton, who will hope for a response when Fulham head north on Saturday, said: "It's very disappointing, more because of the fact that we were on a good run and you want to keep that run going.
"There is an opportunity at home to pick up what are always valuable points in this division.
"We couldn't have done any more in that second-half period to try to get the win and at 1-1, if there was a team that looked like they were going to get the winner, it was certainly us.
"But we conceded two very poor goals and we have got to make sure we pick this group of players up for what will be a very big game for us on Saturday."
Newcastle's disappointment could increase if Barton finds himself under investigation following a 50th-minute incident in which he appeared to catch Pedersen in the midriff with his hand as he ran past.
Hughton did not see the clash, but Allardyce did and said: "I'm not really going to talk about that because I don't want to detract from our victory.
"Whoever will see it will see it and do whatever needs to be done."