Durham, with five first-innings wickets in hand, are 39 runs ahead of Surrey

There were plenty of distractions at the Guildford Festival yesterday, what with the rival attraction of the Farnborough Air Show, the trains chugging past beyond the sightscreen, the buzz from the hospitality tents and the constant threat of rain, but Will Smith maintained his concentration admirably to put Durham in a commanding position.

Smith, 25, a graduate of Durham University who joined the county from Nottinghamshire last season, scored his second championship century of the summer and, with Phil Mustard joining him in an unbroken sixth-wicket stand of 131, Surrey seemed happy to get off the field when bad light brought an early close.

They had high hopes of pressing on towards their first championship victory when Durham started the day on 44 for three but Smith never wavered, Dale Benkenstein joined him in a fourth-wicket stand of 52 and Mustard was troubled only when he found himself on a collision course with the immovable object of Mike Harris, the umpire.

Smith finished unbeaten on 126, having been there for more than five fours, faced 269 balls and hit 15 fours, while Mustard dusted himself down to make 62 off 134 balls with eight fours.

They had made it a dispiriting afternoon for Surrey, who were still full of optimism when James Ormond, the former England fast bowler, who had not taken three wickets in an innings since April 2006, had Benkenstein caught behind as he tried to drive.

Smith went past fifty from 89 balls but Ben Harmison found runs desperately hard to come by. He did not score at all off his first 31 balls after lunch and had made only nine off 57 balls when Murtaza Hussain, the off spinner, put him out of his misery. He got the ball to turn and bounce and it flew off the shoulder of his bat, via the wicketkeeper's gloves, into the hands of Ormond at slip.

That was as good as it got for Surrey. Mustard gave them some hope by sweeping first Chris Schofield and then Hussain just short of backward square leg, but he looked much more assured when he greeted the new ball by pulling Ormond violently for four.

He and Smith will start this morning only 33 runs away from the sixth-wicket partnership record at Guildford, set by Sussex's Bill Athey and Peter Moores in 1996.