Conditional jockey Ryan Mahon demonstrated his value to the Paul Nicholls' stable as he extended the champion trainer's dominance in the StanJames Supporting Greatwood Gold Cup at Newbury.

Pacha du Polder made it six Nicholls victories in the Grade Three handicap since Cornish Sett dead-heated in 2006, and this was the biggest moment in 25-year-old Mahon's career.

Not a model of consistency, Pacha du Polder was revitalised by cheekpieces and his lead was barely challenged in the two-and-a-half miles as he came home five lengths clear of Big Fella Thanks. There were, though, some nasty falls perilously close to Cheltenham for Aidan Coleman (Pepite Rose) Sam Twiston-Davies (Mahogany Blaze) and Nick Scholfield (Micheal Flips). The latter went to hospital for checks.

"That's my first Graded winner," said Mahon."He has his good days and his bad days, but he had every chance on a good day and the first-time cheekpieces have really helped."

Asked if the result was a surprise, Nicholls said: "It was and it wasn't. We always knew he wanted better ground as he showed how good he could be on it when winning at Ayr last year. He ran a shocker when I fancied him in the Old Roan at Aintree and he obviously has his going days.

"I told Ryan if he was having a going day to be very positive. He won't be going to Cheltenham, but he might go to Ayr or Aintree."

Blinkers helped stablemate Michel Le Bon (5-1) reverse a landslide of form in the Barbury International Supporting Greatwood Veterans' Handicap Chase. He had been pulled up on his last two starts, but was in a different mindset as he tracked Tartak and then Hey Big Spender before drawing nine lengths clear.

At Doncaster, Henry Daly fulfilled an ambition by saddling Quentin Collonges to win the William Hill Grimthorpe Chase.

It took a leap of faith to fancy the grey, but he was sent off at 15-2 under Andrew Tinkler, who gave him a very positive ride from the front. After a few breathtaking leaps on the second circuit, his pursuers were soon under pressure with only Mr Moss a serious threat.

Paul Moloney worked wonders to get his awkward ride into contention, but when he drew level on the run-in, the result looked inevitable.

Quentin Collonges was not to be denied, though, and pulled out more for a half-length success. "I've been trying to win this race for a while," said Daly. "The tongue strap helped today and I'd imagine he'll have another entry in the Scottish National. He was well fancied in it last year. He needs a trip, good ground and to go left."

Evan Williams said of Mr Moss: "He's been produced to win but he's not an easy horse to ride. He'll have an entry in the Scottish National and Ayr should suit."

o Katenko has been scratched from the Betfred Cheltenham Gold Cup and the John Smith's Grand National after an emergency operation for colic on Friday ruled him out for the rest of the season.