In the Copa Libertadores 2007, the left-footed playmaker was the hub of Audax Italiano. The team was not able to qualify for the knockout phase due to goal differential. Villanueva was rewarded with a call-up to Chile's Copa América 2007 squad.
On 17 July 2008, it was confirmed by Villanueva's agents and also former club that Villanueva would play for the Blackburn Rovers of the Premier League in England. He also confirmed this on 29 July, pending a work permit being issued.
On 2 August, Villanueva completed his season-long loan move to Blackburn. The club had the option to make the deal permanent, at a pre-agreed fee. Villanueva also agreed terms to extend his contract for a further three years, if the option is exercised.
On 27 August, Villanueva made his debut for Blackburn in a League Cup game against Grimsby Town, a match in which he scored his first goal for the club. He also set up a goal for striker Matt Derbyshire in the 4–1 win. His debut was delayed by a few weeks due to the virus, chicken pox which forced him to stay away from club training facilities, so that he did not pass on the virus to other staff.
On 20 September, Villanueva made his (home) debut in the Premier League as a late second-half substitute against Fulham, his impact was immediate and substantial. Linking up well to provide a looping cross for Roque Santa Cruz to head down for the winning goal, which was converted by Derbyshire.
He made his full starting Premier League debut on 27 September, against Newcastle United at St. James' Park, getting an assist providing a cross for a headed goal for Christopher Samba.
On 5 January 2009, he scored a free kick against Blyth Spartans in the FA Cup giving his team the lead, and on 4 February he assisted two goals against Sunderland in the FA Cup. On 11 April, he played in the Premier League for the first time since Sam Allardyce took charge of Blackburn.
On 15 May 2009, Audax Italiano Villanueva signed for Al Shabab, the Emirati club paid Audax about $5 million. Although he publicly stated he wished to have stayed at Blackburn and tried to established himself in one of the worlds top leagues.
On 4 February 2013, Al Shabab confirms that Villanueva will play on loan at Universidad Católica until 31 May.
Villanueva was in the squad that played in the 2005 FIFA World Youth Championship representing Chile in the Netherlands. He was also capped for the senior squad and played for Chile in the Copa América 2007, where he scored a superb free kick goal against Ecuador on his first official game with the senior squad. He is also credited with an assist during Chile's qualifier game at Uruguay. However, he was not called up to the 30-man preliminary squad for Chile for the South Africa World Cup.