Ayoze Perez has backed Newcastle to carry on surprising those who predicted their Premier League demise.Newcastle secured back-to-back victories in the top flight for the first time since December 2015 by winning 1-0 at Swansea on Sunday.The victory followed up the 3-0 home defeat of West Ham before the international break and provided some much-needed cheer for manager Rafael Benitez, who missed the game after picking up an infection following hernia surgery. Successive wins have also lifted some of the storm clouds hovering over Tyneside after the club's summer transfer dealings. Benitez had made little attempt to disguise his frustration over the lack of squad strengthening and many observers have tipped Newcastle to make an instant return to the Championship. "When the window is open you have to deal with those rumours," Spanish striker Perez said. "But we know the team we have and how strong we can be. "This dressing room is ambitious, we want to win games and that's going to be important this season. "We have got two wins in a row and the most important thing is that we are working on what we have to do. "We have to get the right mentality because we know the season is long and tough."Newcastle set a club record of 14 away wins on their way to winning the Championship title last season. But their Swansea success - secured by skipper Jamaal Lascelles' second-half header - was their first in the Premier League since a 2-1 victory at Tottenham in December 2015. "We had to be in the Championship and it was a tough year," Perez said."Nobody feels good when you get relegated, but we have been working very hard to be in this league."We want to show that we should be playing in this league and these wins will give us some confidence."Swansea have lost both their home games this season and this one was tougher to take than the 4-0 defeat to Manchester United. There had been much excitement surrounding the debut of Portugal midfielder Renato Sanches, the Euro 2016 winner who has joined on a season-long loan deal from B ayern Munich. But Sanches had an underwhelming baptism, making little impact before being withdrawn with 20 minutes remaining."It's going to be difficult for him to adjust to the pace of the Premier League," Swansea midfielder Sam Clucas said."But he's only trained here a couple of days and when he settles in I think we'll see his true quality. "Give him a week or two and he'll be fine. We've all seen what Renato can do in training, he's not at Bayern Munich for nothing and everyone knows the talent he is. "That defeat wasn't down to him, there were 11 players out there and we've all got to look at ourselves."