Yorkshire 276 for 6 beat Derbyshire 268 for 8 by eight runs by

A century from Jacques Rudolph set Yorkshire on their way to an eight-run victory over Derbyshire at Chesterfield to keep them top of Group B in the Clydesdale Bank 40.

The South African scored 105, sharing a second-wicket stand of 144 in 22 overs with Adam Lyth, who made 91, as Yorkshire made 276 for 6 from their 40 overs. Chesney Hughes hit 54 and Wayne Madsen 65 from 57 balls but, despite a late charge from Graham Wagg (27) in his first game since late April, the Falcons came up short on 268 for 8.

Rudolph came into the game with an average of 99.25 in the 40-over competition and the Falcons may have feared the worst when he was dropped on 16 at slip by Chesney Hughes off Tim Groenewald. The South African did not give another chance until he had reached his century as he and Lyth plundered runs after Andrew Gale had become Wagg's first victim in the 12th over.

The Falcons had to wait another 22 overs for their next success and by then Yorkshire were on course for their best 40-over total against Derbyshire. Rudolph reached his fourth 50 in Group B from 52 balls and lifted Garry Park for six over midwicket as he cruised to his second ton in this summer's CB 40 league.

Lyth drove Groenewald into the timber-framed pavilion to bring up the 200 in the 32nd over, and although Rudolph went for 105 off 107 balls when he failed to clear mid off and Jonathan Bairstow was bowled first ball by Groenewald, Anthony McGrath accelerated the scoring in the closing overs.

He drove the left-arm spin of Robin Peterson into the sightscreen at the Lake End and sent a Wagg delivery into the spectators behind the ropes at extra cover as Yorkshire passed the 248 for 5 they made at Chesterfield in 1979. Lyth was finally caught at deep midwicket going for his third six, but McGrath's unbeaten 31 from 17 balls left Derbyshire with a tough chase and they made a dreadful start when Chris Rogers was run out by a direct hit from Lyth in the second over.

But Hughes reeled off some silky strokes to keep his side in the hunt and also pulled Ajmal Shahzad for six as he and Peterson took the Falcons past 50 before Peterson was caught at slip driving at Tim Bresnan. Hughes was looking dangerous, but after completing a 43-ball fifty he drove Steve Patterson to cover.

Madsen and Wes Durston added 74 in 11 overs to keep the game alive before McGrath broke the stand with his second ball when Durston cut him low to point. The Falcons went into the last 10 overs needing 93 but accurate bowling backed up by sharp fielding built up pressure which forced Madsen into a switch hit into the hands of point.

Derbyshire needed 56 off the last five overs and although Wagg smashed an unbeaten 27 off 18 balls, Yorkshire held their nerve to clinch their seventh victory and stay on course for a semi-final place.