Ten-wicket star Mohammad Amir led Essex towards a two-day win over Yorkshire at Scarborough to leave them in sight of a first Specsavers County Championship title in 25 years.
Essex completed their 19-point success, a sixth win in nine matches this season, shortly after tea by chasing only a 33 target for the loss of two wickets.
The visitors are now 46 points clear of second place with five matches remaining, although other results are still to come this week.
This was Yorkshire’s third defeat in their last four Championship matches, and they are now looking at a final month relegation fight.
Having secured a first-innings lead of 118 an hour into the day, Essex then reduced Yorkshire to 14 for three, 37 for six and bowled them out for 150 on the stroke of tea.
Pakistan overseas left-armer Amir was their destroyer in chief, adding five for 54 to his five for 18 in the first innings.
The Pakistan left-armer’s match haul of 10 for 72 from 28.2 overs was a career best match haul.
New ball Jamie Porter was also impressive with three wickets in the first innings and four wickets in the second.
Amir, 25-years-old, added a useful 22 in Essex’s first innings, which advanced from 188 for eight overnight to 231 all out in the first hour of day two.
Yorkshire only took three points following recent defeats against Middlesex and Somerset, the latter coming here in their last match last month.
Amir was exceptional throughout this match in helpful conditions.
Five wickets fell in the morning, including Essex captain Ryan ten Doeschate for 88 - the highest score of the match for either side.
Yorkshire then slipped to 22 for three in their second innings at lunch.
The first hour proved an eventful one, with two wickets falling, Amir suffering a neck injury following a mid-pitch collision with bowler Ryan Sidebottom in the day’s first over and a brief rain break.
Sidebottom later removed Amir caught behind to end a 52-run stand for the ninth-wicket with ten Doeschate before the Essex skipper fell pulling Tim Bresnan to short mid-on.
Wickets continued to tumble.
Porter had Adam Lyth lbw for nought offering no shot two balls into Yorkshire’s second innings before Amir had Alex Lees caught behind for a two-ball duck in the second over.
When Amir trapped Tom Kohler-Cadmore lbw with an in-swinger, despite a half-hearted appeal, Yorkshire were 14 for three in the eighth.
Yorkshire lost their fourth wicket in the seventh over of the afternoon when Harry Brook edged Porter to first slip - 31 for four in the 18th.
Amir then picked up his third, that of Tim Bresnan caught at second slip, with a delivery that did the Yorkshire captain with extra bounce as the score fell to 33 for five after 20.
Amir then had Adil Rashid caught behind in his next over before Andrew Hodd was lbw to Porter in the 25th over - 56 for seven.
Jack Leaning and Jack Brooks (17) then shared 30 for the eighth wicket to give the 5,355 crowd something to cheer about before Leaning and Ben Coad, who made 28, added 45 for the ninth to ensure the visitors had to bat again.
After Brooks was caught at short-leg off off-spinner Simon Harmer, Leaning reached a 114-ball fifty with four fours and a six and went on to hit 70.
Coad edged Amir to second slip before Leaning hit two more sixes over mid-wicket off Porter, who gained revenge by getting him caught at long-on.
Varun Chopra and Nick Browne both fell in the chase, which was completed in 10 overs.