Flintoff underlined his strength and class with a spectacular assault. He reached his 50 from 24 balls, moved into three figures from the 50th delivery he received and finished up scoring his 143 from 66 balls with the help of nine sixes and 15 fours.
"It was one of those days when everything came off," he said."It's been an amazing last few months for me and I can only hope things will continue to go my way."
Flintoff shared a stand of 179 in 20 overs with John Crawley as Lancashire posted a formidable total of 301 for 6 from their 45 overs.
If they thought they were in line for an easy victory they were mistaken. Stuart Law gave the Essex innings a sound start with 55 from 74 balls before Robert Rollins blasted 87 from 51 deliveries but Essex were bowled out for 298.
Flintoff underlined what a fine all-rounder he is becoming by taking three wickets and holding two catches.
Yorkshire made hard work of securing a two-wicket win with 10 balls to spare in their First Division game against Gloucestershire at Headingley. In near darkness the youngster Gary Fellows hit the winning boundary through extra cover off Tim Hancock.
He was put under intense pressure by a mid-innings collapse after Craig White had apparently put Yorkshire on course for an easy win. Needing 146, they made a flying start as White hit two sixes off Jon Lewis and five fours in his 49 made from only 39 balls, but after Yorkshire reached 83 for 3 in 15 overs Gloucestershire fought back well but no avail.
Philip Weston made 125 off 124 balls - his first limited-over century - that included six sixes and 11 fours to set up Worcestershire's 117- run win via the Duckworth/Lewis method against Warwickshire at Edgbaston yesterday.
His opening partner, Paul Pollard, chipped in with 70 in a stand of 149 from 27 overs as Worcestershire compiled an imposing 287 for 4.
Warwickshire lost their openers, Nick Knight and Neil Smith, before an hour's stoppage for rain and then collapsed for 113 in a headlong rush for a revised target of 231 in 29 overs.
In the other First Division game Hampshire's opening batsman John Stephenson hit an unbeaten 71 to guide his team to victory by the Duckworth/Lewis method over Kent at Southampton.
Northamptonshire's Tony Penberthy produced an impressive all-round performance in his side's victory over Surrey at The Oval. He hit an unbeaten 47 and took 4 for 48 in the four-wicket win.
Alec Stewart's torrid time with the bat continued. Dropped off his second ball, the England captain was unable to make the most of his reprieve and made an agonisingly slow 27.
Richard Montgomerie struck an unbeaten 61 and Chris Adams chipped in with 57 as Sussex opened their campaign with victory over Derbyshire at Hove. The hosts, chasing 182, got home by 11 runs on the Duckworth/Lewis method having reached 137 for 3 from 36 of their 45 overs when rain ended play.
Glamorgan's Robert Croft completed a half-century to set up a comfortable 35-run in their Second Division game against Middlesex at Lord's.Reuse content