Ian Blackwell proved to be Surrey's nemesis with bat and ball as the home team subsided to the brink of defeat here in Croydon yesterday. Only rain all day today can prevent them from slumping to their first defeat of the season.
By the close Surrey were just 52 runs ahead with three wickets remaining and a Somerset victory, which would take them to the top of the First Division, looks a certainty, weather permitting.
The failure of Mark Ramprakash even to get close to the hundredth hundred of his career at the sixth attempt was as nothing to the collective inability of Surrey to come to terms with the Somerset spinning all-rounder Blackwell.
In the morning the beefy Blackwell added a further 54 runs to his overnight 104, sharing in a century stand with wicketkeeper Craig Kieswetter to help Somerset build a first innings lead of 120.
In the afternoon Blackwell's left-arm spin accounted for the key wickets of Jonathan Batty and James Benning, as well as that of Surrey's newest signing, Old Whitgiftian Matthew Spriegel.
With Steffan Jones, Ben Phillips and Charl Willoughby – the last taking a wicket not with his usual pace, but with left-arm spin – each picking off a top order batsman, it left Surrey, already handicapped by an injury to their captain Mark Butcher which prevented him from fielding for much of the Somerset first innings, in a mess.
Butcher, who is suffering ankle and knee problems, eventually had to emerge with Spriegel as a runner, his team by then six wickets down. He became victim No 7 when Spriegel was run-out by the quick-witted Zander de Bruyn after Butcher steered a ball to backward point. Spriegel set-off but was sent back, too late; De Bruyn's throw beat him.
Earlier in the day Surrey seamer Jade Dernbach finished with a career best 6-72 – his maiden five-wicket haul – as Somerset lost their last five wickets for six runs in a mere 33 balls.