Ally Brown, who slammed 295 against Leicestershire last week, thrashed a century off only 106 balls for Surrey at The Oval yesterday as Yorkshire's dream of stealing the title from their opponents began to fade away.Brown plundered eight fours and three sixes in his century and he changed the course of the match with a fifth wicket stand of 144 in 31 overs with Nadeem Shahid.Off-spinner James Middlebrook then had Shahid lbw for a commanding 80 but Brown continued his assault to end the day unbeaten on 130 with Surrey 320 for seven and leading by 304.The odds briefly favoured Yorkshire when Surrey dipped to 85 for four but the arrival of Brown soon altered the situation and he was not long in raising the 100 with a cleanly struck six off Middlebrook over wide long on.When he was 21, however, Brown was dropped by Michael Vaughan diving to his right at extra cover off Matthew Hoggard. It was not a difficult chance and the miss proved to be Yorkshire's most costly of the season.It was turning into an unhappy day for Vaughan who had been struck on his right hand during fielding practice in the morning. He took the field at start of play but later retired until after lunch because he was feeling unwell and for whatever reason he was not called upon to bowl.Shahid, who showed plenty of character after being struck on the hand by Chris Silverwood on 29, went to his 50 with a pull off Gary Fellows, while Brown moved to his half-century by cutting Darren Lehmann as Yorkshire went through their various bowling permutations.