He also said he was "relishing the challenge" of playing at a higher level. Porter's transfer fee was subject to a tribunal, with Bury rejecting an initial £25,000 offer from Oldham. With Bury initially asking for £275,000, the tribunal set the transfer fee at £50,000 up front, with Bury receiving £25,000 after Porter had made 15 appearances for Oldham, and a further £25,000 after 30 games. The tribunal also added a 15% sell-on clause for any future transfer fee. Porter scored on his League One debut on 6 August, heading in a Rob Scott throw-in after 24 minutes to help his side to a 2–0 win over Yeovil Town, despite carrying a knee injury. He scored the first hat-trick of his career when Oldham drew 3–3 with Brentford at Griffin Park on 19 November. His trio of goals, all headers, arrived within the first 23 minutes of the game, scoring all three in 12 minutes. An ankle injury left Porter battling for fitness in February, and a knee injury left him only able to make sporadic appearances until the end of the season, requiring specialist treatment in the close season. He ended the season having made 35 appearances in the league and cups, scoring nine goals. In the 2006–07 season, Porter opened his scoring account with a brace during a 2–0 win against Nottingham Forest on 12 September. In March 2007, it was reported that Championship side Stoke City were interested in signing Porter on loan with a view to a permanent £600,000 move in the summer. Oldham manager John Sheridan expressed his anger at "people unsettling our players when we're trying to push for promotion". He also added that Porter had recently "missed five or six chances he'd usually put away. So something's up." After missing five games with knee damage, Porter returned to action in a 1–0 win over promotion rivals Yeovil on 31 March. He then scored his 20th goal of the season on 7 April in a 1–1 home draw with Huddersfield. Having turned down a £650,000 bid from Championship side Plymouth Argyle for Porter during the January transfer window, Oldham managing director Simon Corney believed that the club faced a battle to retain Porter's services in the summer, but said that "we don't want to stand in the way of players who can better themselves at bigger clubs", revealing that there was interest from a Premiership club.