Lee Westwood of England poses with the winner's trophy after the final round of the Ballantine's Championship at the Blackstone Golf Club in Incheon. Westwood won the $3.2 million Ballantine's Championship to keep his place as world No 1. Paul Lakatos / Agence France-Presse

Lee Westwood cemented his place as the world No 1 with victory at the Ballantine's Championship on Sunday and he has already set his sights on the next target: winning his first Major.

The win came amid persistent questions over his position at the top of the rankings. He has claimed the No 1 spot without winning one of the big four tournaments - the Masters, US Open, British Open and PGA Championship.

After victory at the Ballantine's in South Korea - his second win in as many starts - England's Westwood said he was doing everything he could to prepare for the majors and silence the naysayers.

"My next goal is to win a major championship. It's the dream of all professional golfers to get to No 1 in the world rankings, and I've done that," the 38-year-old said.

"I haven't won a Major yet and that's the missing thing, so that's what I gear all my practice towards and my scheduling."

Former world No 1 and six-time major winner Nick Faldo is among critics who have questioned how Westwood can be ranked above his peers while his trophy cabinet lacks the sport's most coveted silverware.

It is Westwood's remarkable consistency that has propelled him to top spot in the rankings, an achievement that has coincided with the slide in form of long-time No 1 Tiger Woods, a 14-time major winner.

The Ballantine's was Westwood's 21st European Tour victory, moving him to joint ninth with Sam Torrance on the list of all-time winners on the tour, and came off the back of victory in the Indonesian Masters on the Asian Tour.

If Westwood can continue the scintillating form that saw him card five birdies and no dropped shots in the final round at the tricky up-and-down Blackstone course near Seoul, he will be hard to beat.

As well as skill and judgement, Westwood showed great mental toughness at the Ballantine's - he went into the weekend 11th in the field, knowing that only a top-five finish would be enough to stop Germany's Martin Kaymer overtaking him in the rankings and ending his reign at the top after just a week.

Westwood first reached the world No 1 spot in October 2010.

He also knew that anything less than a win would give his countryman Luke Donald a chance to jump from third to first in the rankings with victory at the PGA Zurich Classic in New Orleans. Donald finished joint eighth.

Add to that the difficult weather conditions - the tournament began in freezing temperatures, a thunderstorm lashed the course on Saturday, forcing play to be suspended, and swirling winds on Sunday made life extremely difficult - and Westwood's performance was an undeniably professional display.

The European Tour now moves to Barcelona for the Spanish Open on Thursday but Westwood has a fortnight off to prepare for the World Matchplay, also in Spain, and the PGA Championship at Wentworth a week later.