PORT Adelaide is confident it has the game to challenge Collingwood,Essendon and Hawthorn over the next three weeks after upsetting the SydneySwans at the weekend. 

The Power played with real heart against the Swans, confidence broughton through increased fitness levels in 2013 and belief in Ken Hinkley'sno-frills game-plan.

Robbie Gray told AFL.com.au the club's dip in form from rounds five to10 was due to the breaking down of their structures and not fatigue. 

With faith in their ability to run games out until the final siren,Gray, who has returned brilliantly to AFL football after a knee reconstructionearly last season, said his side knew it could take it to its heavyweightopponents. 

"We knew the fitness was always there, [the poor form] was justmore about our structures letting us down," Gray said. 

"We were quite confident heading into the game [against the Swans];we had certain things we wanted to focus on and if we could tick those off –which we did – we knew we'd be right in the game. 

"It was really nice to get that win though and we'll go into nextweek against Collingwood with a lot of confidence." 

With the exception of "a few lapses" in the opening term, Graysaid Hinkley's defence-first style game was executed consistently against theSwans.

The Power's pressure and use of the ball once the Swans turned it oversaw the home side boot nine goals to none from turnovers. 

Gray said they must look to replicate such a performance againstCollingwood next weekend. 

"The defensive pressure that we brought to them and forced them toturn the ball over, opportunities like that came for us forwards because ofguys doing the work up the field. 

"We can only look forward to next week; we've got a pretty toughthree weeks coming up." 

Harry Thring is a reporter for AFL Media. Follow him on Twitter:@AFL_Harry.