Surrey teenager Adam Thomas scored a century on his Championship debut as Sussex were buried under a mountain of runs at the Kia Oval.

The 19-year-old made 120 after opener Dom Sibley strengthened his claims for an England Test recall with a magnificent 187 to take his aggregate for the season to 376 at 62.66.

Surrey were eventually bowled out for 622 with seven of the wickets falling to spin leaving Sussex 264 in arrears.

At stumps Sussex were 76 for 4, which represented something of a recovery having lost two wickets and Tom Haines retired hurt in the first over when he was hit on the helmet grille by the first ball of the innings. Surrey will strongly fancy their chances of winning their first game of the season on Monday.

As well as Sibley played, the third day of this Rothesay County Championship match was all about the talented Thomas.

A flat pitch and tiring attack were ideal conditions, but Thomas was confident and unflustered from the start, playing shots all around the wicket and looking particularly strong through the offside.

Apart from one drive down the ground which only just cleared Haines in the deep he didn’t play a false stroke and The Oval crowd were on their feet when he scampered through to take two runs to deep mid-wicket and become only the ninth Surrey batsman to score a debut century in the County Championship and the first since Aaron Finch in 2016.

Thomas was dismissed shortly after tea when he was bowled trying to force James Coles off the back foot, departing to another standing ovation.

In an eventful start to Sussex’s second innings Haines had to be helped off in some distress after a delivery from Matt Fisher rose sharply off a length and struck him under the grille.

Tom Clark was leg before first ball to one which Fisher swung back into the left-hander’s pads and James Coles edged his third delivery to wicketkeeper Jamie Smith to leave Sussex reeling on 0 for 2.

Jack Leaning was leg before to Jordan Clark and leg-spinner Dan Lawrence got just enough turn to find John Simpson’s outside edge shortly before the close to leave Sussex facing their first defeat of the season.

Earlier, Sussex had done well before lunch to remove three players capable of taking the game away from them quickly.

Ollie Pope signalled his intentions by hitting four boundaries in Fynn Hudson-Prentice’s opening over only to waste a good start when he was caught at second slip trying to guide the ball down to third man.

Lawrence was held at long on and Smith at long off but there was no dislodging Sibley, who passed 10,000 first-class runs on 123 when he took a boundary off Henry Crocombe before hoisting Jack Carson down the ground for six to ease Surrey past Sussex’s 358.

Another six off Carson took him to 150 and he seemed to be cruising towards a double hundred when he tried to belt Carson over the top again and was beaten in the flight to end a vigil that had lasted more than eight-and-a-half hours.

Sibley has now faced a staggering 888 balls in six innings this season, batting for more than 20 hours – after he was last summer’s leading Division One run-scorer with 1,274 runs.

When Haines pinned Jordan Clark Surrey’s lead was 103 but just as Sussex’s had on day one Surrey’s tailed wagged vigorously.

With Thomas now into his stride at the other end Sean Abbott took his cue and they added 161 in 27 overs, a new eighth-wicket Surrey record in this fixture beating the 150 by Robin Jackman and Intikhab Alam at The Oval in 1973.

Abbott (76) was caught at backward point as Sussex took the last three wickets in four balls, but it was a brief respite after 159 draining overs in the field.