Whiteoak returned to winning form in the Starlight Children's Foundation Mares' Hurdle at Kempton on Monday.
Donald McCain's five-year-old struggled to keep tabs on her rivals in the Elite Hurdle at Wincanton on her seasonal debut, but travelled powerfully stepped to three miles for the first time.
Jason Maguire was able to track the leaders into the straight aboard the 6-4 favourite and the former Cheltenham Festival winner skipped away over the final flight to pull seven lengths clear.
"She wasn't right last year but is better now and could be a World Hurdle horse," reported owner Brendan Richardson.
"She didn't run her race in the Champion Hurdle last year and still has plenty of speed.
"There is no reason why she can't win a top race over two miles but the World Hurdle is an option and she did win the mares' race at Cheltenham over two miles and five furlongs."

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