Surrey 252 (Burns 50, Patel 4-58) and 33-1 lead Warwickshire 247 (Barker 62, S Curran 5-44) by 38 runs
Eighteen-year-old seam-bowler Sam Curran took the starring role with five wickets as Warwickshire and Surrey delivered a superb day of Specsavers County Championship cricket at Edgbaston.
Curran, playing only his 13th first-class match, took 5 for 44, including a devastating burst of 3 for 2 in 18 balls, to leave the home side reeling at 101 for 6 in reply to Surrey's 252.
But led by Keith Barker and Ian Bell, Warwickshire recovered to reach 247, a deficit of just five runs, before Surrey reached 33 for 1 second time round in 15 overs up to the close.
On an excellent pitch, offering reward for all types of bowler and demanding high batting skills, the contest has been utterly compelling and of an intensity, quality and drama redolent of Test cricket. A good-sized crowd was engrossed all day and ended it without a clue which way the game will swing next.
Warwickshire began their first innings at start of play and soon lost Varun Chopra, who edged Tom Curran to Jason Roy at second slip. Ian Westwood and Jonathan Trott added 40 from 15 overs before falling in the space of nine balls from Stuart Meaker. Trott, on 13, edged an attempted cut and wicketkeeper Steven Davies parried the ball to Kumar Sangakkara at slip. Westwood reached 45, his championship-best this season, then edged to Roy.
From 91 for 3 at lunch, Warwickshire then had their middle-order ripped out by that high-class salvo from Sam Curran. Laurie Evans and Tim Ambrose were caught by Rory Burns in the gully, in the latter case quite brilliantly, and Rikki Clarke fell lbw to a swinging yorker.
That was 101 for 6 but Bell and Barker added 95 in 28 overs - the biggest partnership of the match so far. While Barker was aggressive, Bell was at his most resolute and it took a near-unplayable ball to remove him when Sam Curran got one to rear off a length and Dominic Sibley made no mistake in the slips.
When Sibley pounced again to end Barker's resistance, Curran had his five-for but Jeetan Patel and Chris Wright ensured that 50 were added for the last two wickets to take their side almost to parity. Patel then had Sibley well-caught by a diving Westwood at short leg in the penultimate over of the day.