Newly crowned world number one Lee Westwood has insisted his predecessor Tiger Woods is more than capable of challenging for top spot again. Westwood, 37, who ended Woods's 281-week reign at the top on Sunday, said: "I've learnt never to write Tiger off." Woods, 34, has struggled since taking a break to deal with personal issues. Any one of Woods, Phil Mickelson and Martin Kaymer could depose Westwood when all four contest the WGC-HSBC Champions event in Shanghai this week. "It's an exciting time for golf," Westwood told the BBC News Channel. "If anyone can put a run together it's so close they could take the number one spot. "But it's taken me a long time to reach world number one, I'm not going to worry about who I am going to lose it to. "You could take it one of two ways. You could either get put off by it and a little bit intimidated or stand up there and try to stay in front of everybody. "It's a great position to be in. Everybody is shooting at you because you've got something everybody else wants." Westwood is particularly wary of Woods, having seen the American produce glimpses of his best in Europe's victory over the United States at the Ryder Cup in October. Woods, without a win since taking a five-month break after admitting to extra-marital affairs, scooped three points in four matches, firing seven birdies and an eagle in 15 holes to beat Francesco Molinari in the final day singles. "It certainly looked at the Ryder Cup like there were green shoots of recovery in his game, " said Westwood. "I've seen him play at his best and I've seen him play with a broken leg when he won the US Open a couple of years ago." For his part, Woods was philosophical about giving up the position he had held since June 2005. "As far as the world ranking is concerned, yes, I'm not ranked number one in the world," he said. "In order to do that you have to win and I didn't win this year. "As far as the emotions go, it is what it is. I've got three more events this year and, hopefully, I can end on a good note. I'm really looking forward to these events and hopefully they will spearhead into a better 2011." Westwood, who has been sidelined by a calf injury since helping Europe win the Ryder Cup, was confirmed as the new world number one after Germany's Kaymer failed to secure the top-two finish at the Andalucia Masters that would have resulted in him usurping Woods. And the Englishman revealed that he was running an errand for his wife when he was told the news. "I'd been sent to the supermarket to buy some mashed potatoes and something else when my caddie rang me to tell me Martin Kaymer wasn't playing very well and I was about to be world number one," confirmed Westwood. "It took me a while to find my shopping after that. It was one of those quiet moments where you have a little smile to yourself." Westwood's achievement is the latest milestone in a rollercoaster career in which he fell from a ranking of four in 2000 to 266 in 2001. "It wasn't much fun and I can sympathise with all the amateurs out there. I hit rock bottom and you have to work your way back up," he added. "I stripped it all down and got back to basics. Mentally your confidence takes a blow and you have to build yourself back up. "In golf, confidence breeds good play and good play brings confidence. It's a vicious circle." In the last two years, Westwood has been in the form of his life, securing top three finishes in four of the past five majors. And the Worksop golfer is targeting the Masters in April to end his wait for top prize at one of the sport's marquee events. "Every other world number one has got one so I'm under a little bit more pressure to win a major," he said. "I'm hoping to get to Augusta next April right where I want my game and contend once more. I just need to produce that extra special thing at the right time." Westwood has been troubled by a problem with his right calf since July and pulled out of the final major of the year, the USPGA Championship, in August. He returned to inspire Europe to Ryder Cup victory before taking more time off for rehabilitation. And after a four-week break, Westwood feels ready to compete against an all-star field in Shanghai. "It's been a slow process," he said. "It's the first time I've ever been injured, I didn't realise how long rehabilitation takes. "I've gradually strengthened it over the last three months and I'm nearly back to where I'd like it to be." Source: BBC