Group A

A brilliant 106 from 20-year-old Alex Hales led Nottinghamshire to a huge 134-run win over Ireland at Trent Bridge. Ireland may have won the recent ICC World Cup Qualifiers, but today was a wake-up call. Hales was partnered by Ali Brown - 19 years his senior but still batting with apparent youthful exuberance - who smashed 89 from just 57 balls. Hales' hundred came from 85 balls as Ireland's attack leaked runs, and Will Jefferson ensured a massive total was set by pummelling 57 from 43. Ireland, set a daunting 347 to win, were never in the contest once they had been reduced to 83 for 4, though Andrew White's unbeaten 50 saw them pass 200. The England discard, Samit Patel, returned economical figures of 3 for 30.

Chris Benham's blistering 108 from 103 balls powered Hampshire to a daunting 300 for 5, a target too great for Leicestershire who were beaten by 46 runs at The Rose Bowl. Hampshire were in all sorts of difficulty at 123 for 5, but Benham took command brilliantly and shared in an unbeaten sixth-wicket stand of 177 with Nic Pothas, the captain and wicketkeeper, who scorched 57 from 64. Their new signing Dominic Cork then picked up two wickets in Leicestershire's reply, but it was Billy Taylor and Sean Ervine who really did the damage, sharing six wickets between them as the visitors' middle order fell away limply. Paul Nixon top-scored with a 47-ball 50, but no one else went on to make a substantial innings.

Group B

James Tredwell tore through Middlesex with six wickets as Kent notched their first win of their summer campaign, winning by six wickets at Southgate. Middlesex lost Billy Godleman early, and Neil Dexter, the former Kent batsman, soon followed. Thereafter Tredwell took centre stage, picking up 4 for 2 in 12 mesmerising balls, including Phillip Hughes for 23. Hughes may not have dominated, but that his 23 was the second-highest rather told Middlesex's sorry tale, as they were rolled for just 133. Ben Scott smacked a quick-fire 29, and Steve Finn did his best at No.11, but there was little else of substance. Kent lost four wickets in reply but were never in serious difficulty, as Darren Stevens carved five fours in his unbeaten 37.

Scotland became the second Associate nation to be reminded of the class in county cricket when Warwickshire hammered them by seven wickets at Edgbaston. The tourists were rolled for a paltry 182. Only their new captain, Gavin Hamilton (51), and the Australian Cameron Borgas (59 from 83) threatened to make life difficult for Warwickshire. Boyd Rankin picked up 2 for 20 from eight highly economical overs, and there were two wickets apiece for Rikki Clarke and Keith Barker. Warwickshire set off in pursuit of 183 in a hurry - Neil Carter hammering 65 from 38 unforgiving balls - before Ian Bell calmly guided them home with 51 from 54, the home side winning in the 31st over.

Group C

Jacques Rudolph's second hundred in a week wasn't enough for Yorkshire whose middle and lower-order couldn't see them across the line in their chase of 270 to beat Gloucestershire at Headingley. Craig Spearman was Gloucestershire's anchor with a fine 92 from just 71 balls, after Kadeer Ali got the innings off to a solid start with 63. Rich Pyrah's 4 for 54 stemmed the flow in the latter half of the innings, restricting Gloucestershire to 269. Yorkshire, however, only had Rudolph to rely on: the next highest score was Andrew Gale's 33 at the top of the order, as Jon Lewis's nagging seamers earned him 3 for 46 to leave the home side's lower-order with too much to do.

Mark Ramprakash's masterful 109 went in vain as Surrey squandered a winning position to lose to Durham by one run at Chester-le-Street. Surrey needed five to win off the final over, bowled by Ian Blackwell, and just two from the last two balls. But at the other end, Grant Elliott drove straight into the waiting hands of Liam Plunkett at mid-off before Jon Batty pulled Blackwell to deep midwicket as Durham clinched a thriller. Ramprakash had appeared to put Surrey into an unassailable position when he brought up his hundred from 96 balls but, instead, he was left stranded. Durham's 266 for 7 was set up by 61 from Phil Mustard and an unbeaten 77 from Dale Benkenstein.

Group D

Glamorgan pulled off a superb eight-wicket win at Chelmsford over the trophy-holders, Essex, chasing down 298 with overs to spare thanks to Gareth Rees's unbeaten 123. Glamorgan's chase was set up by Rees and Mark Cosgrove who put on 80 for the opening wicket: Cosgrove's particularly savage 72 lasted a mere 36 balls, with 10 fours and three sixes. Mike Powell made 33 before Rees, whose hundred came from 122 balls, was joined by Tom Maynard, the son of Matthew and a batsman of great promise. Maynard propelled Glamorgan to their total with 59 from 45 balls, winning with almost four overs to spare. Essex's 297 for 6 was set up by Varun Chopra's 99 and 54 from Grant Flower, but they underestimated Glamorgan's fire.

Lancashire strolled past Derbyshire with embarrassing ease at Old Trafford thanks to Paul Horton (111*) and Mark Chilton (101*) who helped their side chase down 241. Horton cracked six fours in his ton but it was Chilton who really took the aggressive route, lifting two sixes along with six fours as the pair put on an unbroken and match-winning third-wicket stand of 202. Lancashire eased home with 21 balls to spare. Steve Stubbings made 50 and Wavell Hinds an entertaining 95 in Derbyshire's 240 for 6, but Stuart Law, who left Lancashire last season, only managed 18.