By Alasdair Fotheringham
TARRAGONA, Spain, Sept 5 (Reuters) - Belgium's Philippe Gilbert roared past late attacker Edvald Boasson Hagen to take stage 12 of the Tour of Spain on Thursday and claim his first win since becoming world champion last September.
Vincenzo Nibali of Italy remains overall leader and is 31 seconds ahead of Ireland's Nicolas Roche with Spain's Alejandro Valverde a further 15 seconds back.
Norwegian Boasson Hagen blasted away as the pack struggled on a short but punishing rise to the finishing straight in the coastal town of Tarragona but was powerless to stop Gilbert zipping past.
The Belgian made repeated thumbs-up signs to the television cameras afterwards in celebration.
"I was thinking just one word - 'finally' - as I came over the line, because I've come very close a few times but this year has been very difficult," Gilbert told reporters.
"Also there was a lot of pressure with the world championships so soon, so the situation was getting intense.
"Everybody wanted me to win, they wanted to see that first time finally arrive, so you can say it was a very great moment to be able to get that victory," added the 31-year-old.
Following his spectacular 2011 season, with 18 victories including three top Spring Classic races, Gilbert had to wait until late August for his first win in 2012, a stage in the Tour of Spain in nearby Barcelona, before going on to triumph in the world championships.
"This victory will really increase the pressure on me for the world championships (in Florence, Italy on Sept. 29) and on a course like that a lot of people will say I can win again," the BMC rider reflected.
"But I don't see why I should be the only favourite, I could name 10 other riders who might win."
Asked why he had had such a dearth of victories this season, Gilbert, who lost stage seven of the Vuelta to Czech Zdenek Stybar by centimetres, said: "All careers have a high point and mine was 2011, although now I'm still racing at a high level.
"I've always been close to the win, the only difference is win or don't. It's a few percentage power points (which make the difference) and it's not easy to stay on the highest level for years."
The Vuelta finishes in Madrid on Sept. 15. (Editing by Alison Wildey)