Will Smith's 126 not out put Durham in a fine position after two days of the Championship match at Guildford.

Sharing in an unbroken sixth-wicket stand of 131 in 48 overs with Phil Mustard, Smith batted through a day in which his side lost just two wickets.

Only 14 overs were possible before lunch, during which the visitors progressed from 44-3 to 98-4.

But in better afternoon weather, Durham moved to 259-5 by stumps, already holding a lead of 39 over the hosts.

Smith and Ben Harmison got their side back into the game with a watchful fifth-wicket stand of 55. At one point Harmison went 31 balls without scoring.

In the 36th over, however, Smith brought up his 50 off 89 balls with his eighth four, to which he added a ninth and 10th three overs later when he twice cut Murtaza Hussain to the cover-point boundary.

Harmison was held at slip when a lifting delivery from Murtaza caught the edge and deflected off the keeper's left glove but then Smith and Mustard knuckled down to frustrate the Brown Caps' spinners.

Mustard was fortunate when he twice swept the ball high into the air but the unwavering Smith played with calculated aggression.

On the stroke of tea, the 25-year-old went to his second Championship hundred of the season from 215 deliveries with a cut three to deep extra cover off Chris Schofield.

Mustard twice pulled Jimmy Ormond for four in the 84th over and hit the same bowler straight down the ground for another boundary six overs later.

Fortunately for Surrey's struggling bowlers, bad light ended proceedings at 1735 BST.