Surrey 213 (Lawrence 84, Pope 63, Waite 3-19, Leach 3-62) and 342 for 5 (Lawrence 86*, Smith 72, Burns 70, Clark 69) lead Worcestershire 128 (Worrall 6-22) by 427 runs
Leaders Surrey are in a strong position to claim their fourth win of the season in the Vitality County Championship after dominating the second day against Worcestershire at the Kia Oval.
Dan Worrall wrapped up Worcestershire's first innings by claiming the last three wickets in five balls to finish with 6 for 22 as Surrey took a lead of 85.
Skipper Rory Burns laid the foundations with 70 at the start of Surrey's second innings and although Worcestershire fought back after lunch with four wickets in eight overs, Jamie Smith and Dan Lawrence, who was dropped on four, reasserted Surrey's control with a fifth-wicket stand of 115 in 29 overs.
Smith made 72 before Lawrence and Jordan Clark added further punishment with an unbroken sixth-wicket alliance of 108 as Surrey closed on 342 for 5, a lead of 427.
Worrall now has 22 wickets in four games - with power to add in the second innings - after ending Worcestershire's first innings during a high-class spell at the start of the day from the Vauxhall end.
In his fourth over and having bowled a series of inswingers at Joe Leach, he moved one away and Ben Foakes dived in front of first slip to take the edge. Ben Gibbon lost his off bail when the next ball nipped back and although Yadvinder Singh survived the hat-trick he drove airily at his second delivery and Foakes snaffled his 300th first-class catch for Surrey.
All out for 128, Worcestershire were up against it, but their seamers bowled with good control with the new ball and Burns and Sibley took no risks and settled for patient accumulation.
Sibley's first six runs came off 50 balls before he doubled his score by hoisting Gibbon off his pads and over the mid-wicket boundary. The partnership was worth 79 from 29 overs when Sibley nicked a fine ball from Singh on a fourth-stump line that left him off the pitch.
In the next over Ollie Pope was superbly caught by the diving Nathan Smith at leg slip to reward Gibbon's wholehearted endeavours and, having claimed his maiden first-class wicket, debutant Singh took his second in his fourth over when Burns, having passed 50 for the fourth time this season, nicked off and was well held low down at slip by Rob Jones.
Surrey slipped to 115 for 4 in the 38th over after Foakes missed a straight one from Matthew Waite, but Waite was left shaking his head in frustration when Lawrence was put down on the mid-wicket boundary by Kashif Ali having made just three. It felt like a defining moment in the day and so it proved as the sun came out and Lawrence and Jamie Smith built the lead after tea in the best batting conditions of the match.
Smith, playing with increasing freedom, hit 12 fours in a typically enterprising 72 from 109 balls before losing his off stump to Gibbon via an inside edge as he shaped to drive through the covers.
Lawrence followed him to fifty - his second of the match - in the next over and the situation was perfect for Clark to go on the attack. He raced to his half-century off 42 balls, including a six over long-off off Ali, as the lead swelled beyond 400 with 160 runs added in the final session. Both will have their eyes on a century in the morning.