Rory Burns and Rikki Clarke both scored hundreds as Surrey extended their advantage over Nottinghamshire on the second day of their Specsavers County Championship match at Trent Bridge.
Burns made 153 and Clarke scored 111 as the unbeaten Division One leaders totalled 592, a first innings lead of 392 over second-placed Notts.
Surrey’s charge towards their first championship title since 2002 looks like being a personal triumph for Burns, their popular captain, who faced a total of 248 balls, hitting 23 fours and a six.
Sam Curran made 70 and put on 125 for the seventh wicket with Clarke, who reached his first ton since 2012 from 131 deliveries.
Billy Root, on as the seventh different Notts bowler, doubled his haul of first class victims with figures of three for 37.
In the closing 16 overs of the day Morne Morkel removed Jake Libby as the home side closed on 57 for one in their second innings.
Burns, who had begun the day on 97, had to wait for 35 minutes before reaching his third hundred of the summer, with the landmark coming from 162 balls.
Additionally, Burns had to survive a confident appeal from most of the Notts side for a caught behind off Stuart Broad, when on 99.
Luke Fletcher set the tone for a much-improved opening hour for the hosts with a testing spell, which brought him the wicket of Scott Borthwick for 24.
Aaron Finch, playing his first red ball game since the end of the Australian domestic season in March, departed quickly after chipping Broad tamely to mid-on.
The England pace man followed up that wicket with another scalp four balls later. Ben Foakes hoped to have got away with a thin snick as Riki Wessels juggled the chance at first slip but the fielder’s lightning reactions plucked the ball one-handed at the second attempt.
Harry Gurney picked up his 300th first class victim when Ollie Pope fell for 30. At 297 for five Notts were eyeing up only a slender first innings deficit but the next 60 overs saw Surrey hammer home their superiority with a series of punishing stands that stretched their advantage way beyond 300.
Samit Patel took the only two wickets to fall during the middle session, ending Burns’ lengthy sojourn and then darting one into Curran’s pads to end his exhilarating knock of 70, which featured 10 fours and a six.
Clarke reached his first Surrey hundred for 12 years, since making 214 against Somerset at Guildford in his first spell with the county.
Root’s part-time off-spin saw off Clarke, Morne Morkel, whose bright and breezy 28 included three fours, a five and a six, and last man Amar Virdi.
Nottinghamshire’s weary bowlers returned to the sanctuary of the dressing room, nursing hurtful figures. Gurney, Patel and Jake Ball all conceded more than 100 runs and Surrey were further helped, with 52 extras.