Hampshire 219 (Prest 44, Gubbins 43, Worrall 3-37) and 35 for 3 need another 342 runs to beat Surrey 253 (Sibley 100*, Wheal 4-65) and 342 for 9 dec (Sibley 105, Smith 84, Pope 65)
Dom Sibley became the 20th Surrey player to score a century in each innings of a first-class match as Surrey set up a winning position against Hampshire on day three of the Rothesay County Championship match at the Kia Oval.
Jamie Smith's 84 from 113 balls provided the most eye-catching strokeplay as Surrey moved from their overnight 136 for one to 342 for nine declared - setting Hampshire to score 377 to win.
And then, in 16 overs' bowling before stumps, Surrey reduced Hampshire to 35 for three with Kemar Roach pinning Mark Stoneman lbw for three and both Brad Wheal and Sonny Baker, sent in as nightwatchmen, dismissed by Jordan Clark.
Wheal resisted stoutly for 27 balls before being bowled for nine, shouldering arms, and Baker could only fend off a nasty lifter to second slip.
Baker, the 22-year-old fast bowler signed from Somerset last winter, earlier reached near-90mph speeds against Surrey's lower order to claim 5 for 80, his maiden five-wicket first-class haul .
It was Sibley, however, adding 105 to his vital first innings unbeaten 100, who took most of the plaudits as he featured in stands worth exactly 100 with Ollie Pope (65) and 108 for the third wicket with Smith.
The 29-year old opener had literally anchored Surrey's batting effort over both innings and had been on the field for the entire first two and a half days when he tried to hit Liam Dawson's left-arm spin for six and just failed to clear deep extra cover on the ropes.
Sibley also became the first Surrey player since Kumar Sangakkara in 2017, against Middlesex at Lord's, to hit two championship hundreds in a match.
Surrey began day three 170 runs ahead at 136 for one, with both Sibley and Pope already just past 50 and, for the best part of an hour, Hampshire's bowlers kept a tight rein on the scoring rate while also winkling out Pope courtesy of a sharp legside catch from keeper Ben Brown when the England batsman attempted to flick away a rising off-cutter from Kyle Abbott.
Smith, however, got away quickly with crashing boundaries off Brad Wheal and Baker and only the introduction of Liam Dawson's steady left-arm spin from the Vauxhall End brought Hampshire any modicum of control as Smith cruised to 45 by lunch, taken with Surrey 224 for two.
Sibley, having added 33 in the morning session to reach 88, completed his second century of the match - and the 24th first-class ton of his career - with two runs to fine leg.
Ben Foakes came and went for one, hitting Brett Hampton's medium pace to short mid wicket and there was then a near two-hour delay for bad light and rain from 2.45pm, when Surrey were on 282 for four and 316 runs ahead.
Some of Smith's strokeplay was sumptuous although, on 24, he did edge Baker just short of slip before regaining the initiative by hoisting the same bowler high over mid wicket for six.
One on-driven four from Smith, off Hampton and taking him to 68, was perhaps the shot of the day but he was then out to the first ball he faced following the weather interruption, swinging Baker high to deep square leg where Tom Prest took an outstanding low catch diving forward. Smith had struck two sixes and nine fours.
Baker then had Dan Lawrence caught down the legside by Brown for 23 before yorking both Clark (1) and Matt Fisher (2) with pacy inswingers. He was on a hat-trick after having Dan Worrall caught behind first ball, but Roach kept him out and the declaration came at the end of the next over with Ryan Patel unbeaten on 30.
