Rob Key's 270 not out is his highest-ever score. Picture: Barry Goodwin

Kent captain Rob Key put his early-season batting problems firmly behind him with a career-best 270 to lead Kent to victory by an innings and 45 runs against Glamorgan at Cardiff.

The victory put Kent back on the top of the LV County Championship Division 2 table and a delighted Key, whose innings surpassed the 221 he made for England against the West Indies at Lord’s in 2004, said: "I felt in good nick throughout the knock and I’m definitely coming back into form.

"I didn’t score many early season but I got the ton against Surrey and now feel that I’m batting well again."

Kent have a 13-point lead over second-placed Derbyshire, and Key added: "We are playing some good cricket and I’m delighted that we have gone top again."

The hosts made 317 in their first innings, although barely 20 overs were bowled on day two because of rain. Ryan McLaren was Kent’s leading wicket taker with 4-51.

Key and Geraint Jones led the response before Jones was out for 68. Martin van Jaarsveld got within four runs of a century and further runs from Justin Kemp put Kent in command.

After resuming on 444-4 on Saturday morning, Key and Kemp took less than an hour to add a further 113 before Kemp was removed for 90.

Key eventually declared on 557-5, and then off-spinner James Tredwell took centre stage with a spell of 4-48.

Only Michael Powell (60) offered any real resistance as he and skipper Jamie Dalrymple (24) put on 82 for the fourth wicket, but once they departed Glamorgan crumbled to 195 all out.

Key decided to declare when he was 270 not out, rather than trying to take his score past 300, but he had no regrets, saying: "We wanted to get them in and attack them. We wanted to bowl them out because we knew the wicket was deteriorating."