Jonny Bairstow batted through the third day at Arundel to score his first Championship hundred since April 2011 and put Yorkshire in a position to force victory against Sussex.
The 23-year-old, who lost his England place to Matt Prior after playing in the last two Tests of the Ashes campaign, showed great powers of concentration on a slow pitch which inhibited his attacking style.
When Yorkshire declared on 471 for seven with ten overs of the day remaining Bairstow had compiled a chanceless 161 with his side 154 runs in front.
Sussex openers Chris Nash and Luke Wells survived to reduce their arrears by 21 at stumps but Yorkshire will feel they can still force victory on the final day, especially with Sussex captain Ed Joyce, who was off the field for much of the day with a sore hamstring, unable to bat until No.7.
While Bairstow celebrated there was agony for Jack Leaning who fell one short of a maiden hundred in only his fifth first-class match.
The 20-year-old, who batted for a shade over five hours, came down the pitch looking to hit off-spinner James Tredwell over the top but his drive was brilliantly caught one-handed by the bowler, in his follow through.
Leaning nonetheless departed to a standing ovation after facing 257 balls and hitting 12 fours.
Together with Bairstow he put on 125 in 42 overs and after Aaron Finch was leg before playing back to Steve Magoffin, Bairstow joined forces with Tim Bresnan to bat through the afternoon session and build Yorkshire’s lead.
Bresnan offered one chance on 63 when he was dropped at slip off Tredwell and added five more runs before Magoffin bowled him with a nip-backer to end a stand of 138 in 50 overs for the sixth wicket.
Bairstow pushed on but it said much for the slowness of the pitch and the accuracy of the Sussex attack that he hit just eight boundaries in just under six hours at the crease, during which time he faced 290 balls.
He also hit three sixes, going down the pitch to twice loft Tredwell over long on and a pull off Lewis Hatchett.
Tredwell’s marathon spell of 59 overs was the most sent down by any Championship bowler this season in a single innings and he picked up a third wicket when Azeem Rafiq drove to cover.
Magoffin finished with four for 81 from 42 overs and Sussex’s fielding remained solid even though they had been in the field for the best part of six sessions with wicketkeeper Ben Brown conceding a solitary bye in 173 overs.
Bairstow was delighted to have been at the crease for nearly seven hours and help put his side in a position to force victory on the final day.
“I’m really tired but that’s the way I want to feel because it means I have spent a long time in the middle.
“The wicket is very slow and you have to sit in sometimes, and they kept coming at us. But I felt good and it was great to make a big score. I have felt good in recent weeks and thought I was due some runs.
“We’re a positive side and we’ll be doing all we can tomorrow to try and win the game.”
Magoffin, who was Sussex’s most successful bowler with four for 81 from 42 overs, admitted that it had been a hard slog for his side.
“It’s very slow but there is very little movement either and once the ball is 10-15 overs old it can be like bowling with an orange,” he said.
“I thought we stuck at our task really well in the field. It was tough to be out there for the best part of two days but we were disciplined. “We just need to bat through the final day and I’m sure we will.”