LONDON - Australian Darren Lehmann struck his fifth century of the season on Thursday to keep Yorkshire firmly on course to win its first English county cricket championship title since 1968.

Lehmann's unbeaten 141 against Leicestershire powered division one leaders Yorkshire to 3-267 in its second innings -- an overall lead of 376 at the close on the second day of the four-day match at Leicester.

The South Australian emphatically pressed home the advantage which Yorkshire had gained earlier in the day by bundling out the home county for 121 to lead by 109 on first innings.

Lehmann, who was averaging 87.28 in the Championship before the current round of matches, batted for 248 minutes, faced 213 deliveries and hit 20 fours.

He put on 138 for the third wicket with England batsman Michael Vaughan (47) and 106 in an unbroken fourth wicket stand with captain David Byas (37 not out).

Openers Jimmy Maher and Mike Hussey were two other Australians in form. Queenslander Maher hammered an unbeaten 102, containing 14 fours, to give Glamorgan a solid start of 2-188 in reply to Essex's first innings of 327 on the second day at Cardiff.

Western Australian Hussey hit 93 to lead Northamptonshire to 3-281 after Lancashire declared its first innings at 6-600 on the second day at Old Trafford.

Hussey faced 116 balls and hit 15 fours and one six.

Earlier, Lancashire captain John Crawley extended his overnight 208 to 280, one short of his highest score for the county, against Somerset in 1994.

Champions Surrey, struggling in sixth place in the nine-team table, was indebted to paceman Martin Bicknell for its total of 258 against Kent on the first day at Canterbury.

Bicknell came in at 6-95 and led a recovery by hitting 78 off 157 balls, with nine fours.

England discard Graeme Hick completed an innings of 201 for Worcestershire in its 524 all out on the second day against Warwickshire at Edgbaston.

© 2001 AAP