Defour tried to force a transfer by threatening to leave, using a Belgian law that allowed professional athletes on fixed-term contracts to leave their employers before the end of the stipulated term, but Ajax did not express a renewed interest in his services, and he ended up signing for Standard Liège for a much-reduced transfer fee, effectively breaking a gentlemen's agreement between Belgian sides not to sign under-contract players using the aforementioned law.

[20] The following 13 March, for the same competition but in the round of 16, he was booked twice and subsequently sent off in the 49th minute of the second leg of the tie at Málaga CF, as the northerners lost 2–0 at La Rosaleda Stadium and 2–1 on aggregate.

On 25 January of the following year, when playing at Standard Liège, he was sent off for deliberately kicking the ball at home fans who had unfurled a banner depicting his severed head under the slogan "Red or Dead".

His ejection caused the visiting supporters to rip out their seats and throw them onto the pitch,[22] and the banner received criticism from both the Royal Belgian Football Association and the league.

[24][25] He made his competitive debut four days later, starting in a 2–0 home win over Liverpool in which he helped create the second goal by Andre Gray but was substituted early in the second half due to a lack of fitness.

[26] On 10 September, also at Turf Moor, he scored his first goal for his new team to open a 1–1 draw with fellow promotee Hull City, and was praised after the match by manager Sean Dyche.

[37] He made his debut on 11 May in a friendly against Saudi Arabia in Sittard in the Netherlands, playing all but the last minute of a 2–1 win;[4] he scored his first goal on 6 September 2008, in a 3–2 victory over Estonia at his club ground the Stade Maurice Dufrasne for the 2010 FIFA World Cup qualifiers.

[39] He was selected for the finals in Brazil by manager Marc Wilmots,[40] making his debut in the competition on 26 June in the third group stage match against South Korea after Belgium had already won their first two outings and sealed qualification, and was sent off in the last minute of the first half of the eventual 1–0 win after a rash tackle on Kim Shin-wook.

[44] In his first game two days later, he won 2–0 at home to Standard;[45] he reached the final of the Belgian Cup in his first season, losing 2–0 to Mark van Bommel's Antwerp.