Swansea reach League Cup semi-final

Swansea City's Michu celebrates a goal scored by Garry Monk (unseen) during their English League Cup soccer match at the Liberty Stadium in Swansea, South Wales, December 12, 2012.

LONDON (Reuters) - Swansea City booked their place in the semi-finals of the League Cup after an own goal by Seb Hines secured the Premier League club a 1-0 victory over second-tier Middlesbrough on Wednesday.

The Middlesbrough defender headed a Swansea corner into his own net in the 81st minute after an evenly matched quarter-final at the Liberty Stadium in Wales.

Middlesbrough enjoyed the best of the first-half chances and came close to breaking the deadlock when Grant Leadbitter side-footed a shot that had Swansea goalkeeper Gerhard Tremmel scrambling to save.

Swansea upped the pressure after the break and Jonathan de Guzman's free-kick was tipped on to the bar by Middlesbrough keeper Jason Steele before Hines headed into his own net.

"It was a very important victory and now we're in the last four," Swansea manager Michael Laudrup said.

"They are a good side, and we may be playing them next year in the Premier League. In the second half we came out and dominated like we normally do at home."

Fourth-tier Bradford City upset Premier League Arsenal on Tuesday to secure a semi-final spot alongside Aston Villa who beat Norwich City.

Chelsea, who are playing in the World Club Cup in Japan, face Leeds United in the final last-eight clash on December 19.

(Reporting by Toby Davis; editing by Robert Woodward)