Jonny Bairstow scored his first first-class century in a little over two years as Yorkshire had much the better of the opening day of their County Championship promotion battle with Middlesex at Headingley.Bairstow, 34, has struggled for form of late and, within the last two months, has been dropped from all England sides. But he refuses to be written off, as this excellent 107 not out off 130 balls suggests.He underpinned Yorkshire’s 372 for 5 from 96 overs and was supported by half-centuries for Adam Lyth and George Hill. Luke Hollman returned 3 for 99 from 27 overs of legspin.Yorkshire started this game in third place in Division Two, three points behind Middlesex in second. Having won the reverse fixture at Lord’s in April, Middlesex knew that completing the double would give them a stranglehold on the race for a return to the top flight. But they have significant work to do.Bairstow is at his most dangerous when he has a point to prove, and was challenged to regain his best form earlier this week by England selector Luke Wright, after he was left out of ODI and T20I squads to face Australia. This was his first first-class hundred since his twin tons against India at Edgbaston in 2022, and his first for Yorkshire since May 2016.