Lancashire 17 for 0 trail Surrey 201 for 8 dec (S Curran 56*, Mahmood 4-50 ) by 184 runs
Saqib Mahmood took a career-best 4 for 50 as Lancashire had the better of the opening day of their Specsavers County Championship clash with Surrey at Old Trafford.
With Surrey beginning three points ahead of third-placed Lancashire, it's a match where the winners will finish second in Division One.
Surrey lost eight wickets before choosing to declare having reached 201 for 8 - their first batting point thanks to a half-century from Sam Curran - which denied Lancashire a third bowling point.
"My first first-class game at Old Trafford and it's one I won't forget in a hurry," Mahmood said "From a bowling point of view we couldn't really have done much more. To get them to 200, the wicket looks like it's flattening out now.
"I was so annoyed they declared, I'm on four wickets and every ball I felt I was going to get a wicket and they go and declare so I wasn't very happy if I'm honest!"
On the declaration, Surrey coach Michael Di Venuto said: "We wanted to have a crack at them tonight and knock a couple over but it wasn't to be. The rewards didn't come for us but tomorrow is another day.
"Our tail hasn't been the best this year so to save wasting time and to get those nine overs to try to get a couple of wickets was the intention. Get the game moving, that's the intent. It was the last thing they were expecting."
The visitors decided not to exercise their right to opt to bowl and the toss was won by Lancashire, who did choose to do so, therefore giving both captains the outcome they wanted.
There were a couple of early chances for the hosts as Tom Bailey forced Rory Burns into drives that Dane Vilas and Rob Jones got hands to high above their heads but couldn't hold.
Burns and Mark Stoneman, the Championship's third and second highest runs-scorers respectively, shared 47 for the first wicket before Burns chipped Mahmood to Shivnarine Chanderpaul at mid-on to depart for 18.
Lancashire struck again before lunch, legspinner Matt Parkinson producing a superb delivery that spun back at Stoneman who left alone the ball that crashed into his stumps.
That brought Kumar Sangakkara to the crease in his last first-class game and he was welcomed with a guard of honour by Lancashire's players before guiding Surrey to lunch at 72 for 2.
But it was a frenetic innings from the Sri Lankan great, who has made eight Championship centuries this season. Having launched Stephen Parry for six before lunch, he fell for the short-ball trap - hooking a bouncer from Mahmood to Rob Jones in the deep for 14.
"We had a plan on how to bowl to Kumar Sangakkara at lunch and to come out and nail the plan, I couldn't quite believe it had come off," Mahmood said. "It is a great scalp."
Lancashire struck twice more before an early tea was called. Mahmood, playing in just his fourth first-class game, nipped one back at Scott Borthwick to trap the left-hander lbw for 30.
Stephen Parry then picked up Surrey's fifth wicket by ripping one past the outside edge of Ben Foakes' bat with what turned out to be the final ball before tea - which was called early due to a combination of bad light and drizzle. Surrey were 112 for 5 at the interval and Lancashire were in the ascendancy.
But a half-century stand after the resumption between Ollie Pope and Sam Curran held up the Lancashire charge. They could add just four more however as Pope overdid the attacking side of the stand, attempting to launch Parkinson down the ground but the ball turned past his outside edge and Alex Davies completed the stumping.
Mahmood sealed his career-best figures by trapping Rikki Clarke for 7 with one that kept a little low before Gareth Batty came and went without scoring.
Curran though carried on with his extremely impressive innings, passing his half-century from 106 balls. He went on to reach an unbeaten 56, taking Surrey past 200 and to their first batting point. At that stage they promptly declared.
Alex Davies and Rob Jones negotiated a tricky period to close on 17 without loss.