Punter Paul Dean will collect at least £250,000 today after deciding to partially cash out his £5 accumulator.

Mr Dean, from Stockton, stood to bank £511,225 if he allowed the bet to roll on and Envoi Allen won the opening Marsh Novices’ Chase.

However, he has opted to take Betfair’s cash-out offer of £275,000 after overnight deliberation.

Mr Dean tweeted: “After celebrations last night, four hours sleep and an hour walk at 5am, I’ve decided to take a partial cash-out offer. With other bets, my position on the race is £322,000 Envoi or £250,000 the field.”

The accumulator kicked off with Golden Horde (12-1) and Hello Youmzain (10-1) winning the Commonwealth Cup and Diamond Jubilee Stakes respectively at Royal Ascot, before Shishkin, who he had backed at 4-1, claimed the Arkle and Bob Olinger, who he had at 25-1, lifted the Ballymore.