Adam Lyth scored his sixth hundred of the season as Yorkshire took a giant stride towards securing the LV= County Championship title on day one of their penultimate match against Nottinghamshire at Trent Bridge.
The visitors charged to a score of 319-4 on the first day of their Division One match against trophy rivals Nottinghamshire, with Whitby-born Lyth - fresh from scoring 251 against Lancashire last week - furthering his claim for a place in England's Test side.
Lyth, who is being widely back for an international call-up, scored 122 and made his runs from 231 balls, with 14 fours, sharing in an opening stand of 176 with Alex Lees, who made 86.
Gary Keedy (2-93) broke their partnership in the afternoon session, having Lees caught by Riki Wessels at short leg, before Lyth eventually offered the former Lancashire spinner a simple caught and bowled.
Joe Root, captaining Yorkshire in the absence of the suspended Andrew Gale, made just 11 before being given out lbw off the bowling of Harry Gurney, but his international colleague Gary Ballance ensured the White Rose remain on course to claiming a crucial victory.
The visitors arrived at Trent Bridge knowing victory over Nottinghamshire would seal the County Championship and Ballance - unbeaten on 82 - is set to continue their attack alongside Jack Leaning (8 not out) on Wednesday with Yorkshire needing 81 more runs to claim maximum batting points.
Warwickshire kept their slender hopes of getting hands on the Division One trophy alive with a defiant display against Northamptonshire on the opening day of their clash at Edgbaston.
Home captain Varun Chopra won the toss and elected to bowl, a decision quickly vindicated by seamers Oliver Hannon-Dalby (4-57) and Keith Barker (4-61) as Northamptonshire were dismissed for just 273.
Opener James Kettleborough was the mainstay of their innings, hitting 10 fours on his way to 71, and all-rounder Ben Duckett (55) was the only other man to break the half-century mark as Warwickshire's bowling attack took centre stage.
The hosts lost Ian Westwood for just one, but fellow opener Chopra (43 not out) and William Porterfield (24 not out) ensured Warwickshire reached the close with no further scares, ending the day on 79-1 as they seek a maximum-points win to keep pace with the top two.
At Hove, Lancashire's bid to avoid an immediate return to Division Two stuttered as they were bowled out for 320 by Sussex on day one.
Seamer Steve Magoffin (4-96) and Pakistan spinner Ashar Zaidi (3-36) took wickets at regular intervals as the hosts dismissed Lancashire, with both sides claiming three bonus points.
Lancashire are favourites to rejoin Northamptonshire back in Division Two, no less so after struggling to 320 all out. The visitors needed No 8 Luke Procter to make a defiant 81 not out to initiate a recovery from 148-7.
Sussex openers Chris Nash and Luke Wells played out two overs without scoring before the close of play.