Durham are offering free admission at their Riverside ground on Friday and Saturday to watch their team clinch their second successive LV County Championship title.

With defeat out of the question after they amassed their record total of 648 for five declared, the guarantee of four points for a draw means they need to take six wickets in the first 120 overs of Nottinghamshire's innings to end their opponents' and Somerset's mathematical prospects of stopping them wrapping up a second successive title.

With Nottinghamshire closing the second day on 65 for two, Durham still have 96 overs to take the four wickets.

Mark Davies took the first two, with Steve Harmison out of luck in a hostile spell on the run-laden pitch.

Durham declared straight after beating their previous best of 645 for six against Middlesex at Lord's in 2002.

They had four century-makers in an innings for the first time in Michael Di Venuto, Kyle Coetzer, Dale Benkenstein and Shivnarine Chanderpaul.

In his fifth season with the club, former captain Benkenstein's century was his 15th for Durham - taking him to the top of their list.

"It probably wasn't one of my best," he said.

"They were struggling with injuries, but we had a target and we just set out to reach it.

"I really enjoyed leading the side to their first title last season. But it was time to hand over, and Will Smith has done unbelievably well."

Chanderpaul took great care over completing his 50th first-class century, patting back the last four balls before tea from Samit Patel when he was on 99.

The West Indian reached his hundred shortly after the break courtesy of a misfield by Darren Pattinson, which summed up the display by a visiting side for whom nothing would go right.

In addition to losing captain Chris Read and Charlie Shreck through injury on the first day, Mark Ealham was unable to bowl today because of a rib problem picked up when running out Coetzer.

The injuries forced Patel to bowl 60 overs and he had conceded 193 runs before he took his only wicket, when Ian Blackwell drove to long-on.

Substitute wicketkeeper Bilal Shafayat held three catches, starting when Di Venuto pushed forward and edged the first ball of the day from Luke Fletcher to depart for 219.

Fletcher also had Will Smith caught down the leg side by Shafayat for 26 as two wickets went down in the first 10 minutes. But then Chanderpaul put on 203 with Benkenstein, whose century came off 170 balls, compared with 209 for his partner.

Shafayat held his third catch when Benkenstein edged an attempted big hit off Alex Hales.

When Nottinghamshire batted Scott Newman, the left-hander on loan from Surrey, looked quite comfortable until Davies brought two balls sharply back into him. The second lbw appeal was upheld; then Mark Wagh flashed a catch to Liam Plunkett at gully.