Sam Arthurton's unbeaten century was not quite enough for Norfolk as they fell six runs short of victory in a thrilling finish against Shropshire at Manor Park yesterday.

Norfolk's pursuit of a victory target of 291 looked to be faltering before Arthurton smashed successive sixes in the 47th over to get them back on track. With 11 needed from the last eight balls and six wickets in hand, the home side were favourites, but three wickets in three balls effectively put paid to their hopes.

It was a third successive victory for Shropshire in Group Two, while Norfolk will now probably need to beat Lincolnshire and Suffolk to qualify for the quarter-finals.

Arthurton, who finished on 106no from 104 balls, including seven fours and three sixes, admitted to mixed feelings after the game: 'I am disappointed,' he said. 'It's always nice to make a contribution and in the end we were not far off. We played some good cricket, there were just odd pieces of cricket where we lost it.'

After getting slightly bogged down mid-innings against the Shropshire spinners, Arthurton's late assault almost rescued his side and he added: 'There are always parts of a game and moments which turn the game and you will have patches where the run rate slows down, but at least we got to that stage at the end without losing too many wickets. We stayed in it with wickets in hand which gave us a chance.'

A fifth wicket stand of 75 with Stephen Gray took Norfolk to the brink of victory and Arthurton said: 'You never think you've got it won, but I think we had them for a few minutes at the end there. We built a partnership and that took the pressure off. We took it down to the last over and you have to give their bowler credit, he bowled it really well.'

Despite the defeat, Arthurton remains confident about Norfolk's chances of reaching the last eight: 'We won the first game so it's not the end of the world,' he said. 'There's no need to panic – if we play some cricket like we did today we'll give ourselves a good chance of going through.'

Shropshire chose to bat first and Norfolk newcomer Dominic Reed made a flying start to his career with the county by taking a wicket in his first over as visiting skipper Richard Oliver obligingly guided the ball to Luke Caswell at slip.

But from there it was pure toil for Norfolk as former Nottinghamshire batsman Bilal Shafayat joined Ed Foster in a second wicket stand of 126.

A huge total seemed on the cards, but the partnership was finally broken when Arthurton's fine throw from the deep ran Foster out for 75.

The introduction of Caswell helped Norfolk apply the brakes as the left arm seamer used the cloudy conditions to his advantage. Joe Leach chipped a catch which just carried to Peter Lambert at midwicket and Richard Foster was caught behind by Gray, standing up to the stumps.Caswell bagged a third wicket when Jono Whitney scooped the ball to square leg, leaving Shropshire on 190 for five.

Shafayat's busy innings, which included a couple of effortless sixes, was ended by the persistent Martin Addison, who picked up two more victims in the closing stages.

But Tom Cox's aggressive, unbeaten 44 helped Shropshire crucially add 60 in the final five overs to finish on 290 for eight.

Norfolk openers James Spelman and Ben France put on 76 before France departed, bringing Arthurton to the crease. He and Spelman stylishly advanced the score, before Shropshire spinners Alex Blofield and Elliot Green began to exert control.

The return of the seamers helped Spelman break the shackles as he hit successive fours off Leach, before the bowler got his revenge with a perfect yorker in the same over.

The eventful over continued with Trevor Ward top edging his first ball for four, before being given out lbw to the next delivery.

Peter Lambert's six brought up the 200 but when he was out soon afterwards, Norfolk appeared to be losing their way.

Gray joined Arthurton to rectify that and the latter produced two beautifully picked up sixes off Michael Barnard in the 47th over before reaching his century.

When Gray pulled the first ball of the penultimate over for six, Norfolk needed 15 to win, but the wicketkeeper then holed out to long off.

With 11 needed from the final over, Caswell was bowled first ball by Leach and then Bradshaw smashed his first delivery onto the stumps at the non-striker's end – before being run out as the bowler gathered the ball and ripped the stump out of the ground.

Arthurton's audacious flicked four raised hopes, but a dot ball and a scrambled single left Norfolk skipper Chris Brown needing to hit the last ball for six. He was unable to connect – and as a final insult was stumped as he wandered away from the crease in disappointment.