|LV= County Championship Division Two, Guildford (close, day three)|
|Surrey 406 & 276-8: Harinath 104, Wilson 54; Hogan 5-44|
|Glamorgan 437: Wagg 200, Wallace 92; Curran 3-76|
|Surrey lead by 245 runs|
|Surrey 6 pts, Glamorgan 7 pts|
Glamorgan all-rounder Graham Wagg and Surrey opening batsman Arun Harinath shared the limelight on a record-breaking third day at Guildford.
Resuming on 116, Wagg reached his first double hundred from 215 balls as the visitors made 437 - a lead of 31.
The 32-year-old added 105 for the final wicket in just 11 overs with Michael Hogan before being dismissed for 200.
Harinath's 104, his second ton of the game, helped Surrey to 276-8 at stumps, despite five wickets for paceman Hogan.
Wagg hit 21 fours in his 253-minute long knock, while his 11 sixes were the most by a Glamorgan batsman in a County Championship innings.
His 200 also equalled Dominic Cork's record for the highest score by a number eight in English domestic first-class cricket, which he made against Durham in 2000.
Harinath's 156-ball stay at the crease, to go with his 120 in the first-innings, was ended when he was trapped lbw by Andrew Salter, but with Surrey holding a lead of 245 with two wickets left, all results are still possible on the final day.
Surrey opener Arun Harinath told BBC London 94.9:
"I'm very pleased [to score a second century of the game], shame I couldn't have gone on, but on a personal note it's always nice to get some runs and hopefully tomorrow we can push on and get that win.
"I'm obviously very happy with three figures because that's what we play the game for.
"300 would be a great chase for them to have on a last day wicket, we know it's going to do a bit and spin."
Glamorgan all-rounder Graham Wagg told BBC Radio Wales Sport:
"It was quite unreal, my little six-year-old boy Brayden said before the match 'Daddy get four wickets and score two hundred' and we laughed at him but I think we'll do the lottery now!
"I just knocked it down to fine leg on 198 and we ran two, and the emotions were running so high it's hard to explain.
"But I'd like to mention Michael Hogan who ran in all day and bowled phenomenally to pick up five wickets."