|LV= County Championship Division Two, Colwyn Bay|
|Lancashire 698-5 dec: Petersen 286, Prince 261; Lloyd 3-164|
|Glamorgan 348 & 193 (f/o): Cooke 56; Kerrigan 4-28, Lilley 3-38|
|Lancashire won by an innings and 157 runs|
|Lancashire 24 pts, Glamorgan 3 pts|
Division Two leaders Lancashire moved closer to promotion by beating Glamorgan by an innings and 157 runs.
No play was possible before 13:00 BST because of rain in Colwyn Bay.
Sixth-wicket pair Chris Cooke and Andrew Salter held up Lancashire's push for victory, but the hosts then lost their last five wickets for 12 runs to be bowled out for 193.
James Faulkner dismissed Cooke (56) before Simon Kerrigan (4-28) and Arron Lilley (3-38) wrapped up the tail.
|Beaten in North Wales, unbeaten in South Wales|
|Glamorgan suffered their first home defeat of the season, but remain unbeaten back in Cardiff. It was, however, their sixth successive failure to win in completed games against Lancashire.|
|Alviro Petersen's double century took him past the career landmark of 13,000 first-class runs.|
Lancashire's win earned them a maximum 24 points, putting them 32 clear of Surrey in second place and 68 ahead of Glamorgan in third.
Their victory was set up by a 501-run partnership between Alviro Petersen and Ashwell Prince during the first two days - they became only the 13th pair in first-class history to share a stand of 500 runs or more.
The visitors required only five wickets on the final day and achieved the task comfortably despite the rain delay, helped by off-spinner Lilley removing Craig Meschede and Graham Wagg in the space of three balls.
Left-arm spinner Kerrigan ended Salter's obdurate 34 from 101 balls and finished the match with the dismissal of Michael Hogan, who was caught by Kyle Jarvis at cover.
Glamorgan head coach Toby Radford told BBC Wales Sport:
"Having had a great run, going unbeaten before Chelmsford, suddenly you get two losses on what's been an 18-day road trip.
"Everyone's a bit tired and want to refresh before Gloucestershire at Swansea (on 6 August). This comes at a good time because those last five Championship matches are massive.
"In terms of whether we can still get promotion or be in a place to justify how well we've played for the majority of the season."
Lancashire head coach Ashley Giles:
"We spoke of the importance of the game last week and this will now give us breathing space at the top of the table, which is very important.
"This has made a big statement and we want to repeat this performance in our next game. It was, of course, a big bonus to win the toss on such a good pitch and we also said that we only wanted to bat once.
"We then watched the outstanding partnership between Alviro Petersen and Ashley Prince and we knew that, if we could bowl well, we were in for an innings victory."