Yorkshire 362 (Lyth 109, Masood 60,Thompson 53) and 0 for 1 (Lyth 0*, Sanderson 1-0) lead Northamptonshire 301 (Procter 116*, Fernando 4-48) by 61 runs
Northamptonshire captain Luke Procter marshalled his side's fightback in their Vitality County Championship game against Yorkshire with a tenacious unbeaten century - his first in almost two years.
Procter, who had already passed fifty five times this season without converting any of those knocks into hundreds, remedied that as he sparked Northamptonshire's recovery from 181 for 7 on day two at Wantage Road.
The skipper finished 116 not out, sharing stands of 50 and 58 respectively with tailenders Ben Sanderson and Jack White to ensure the home side totalled 301, a deficit of 61 on Yorkshire's first-innings 362.
Sri Lankan left-armer Vishwa Fernando took 4 for 48 on his debut for the visitors, who lost nightwatchman Dom Leech to the final ball of the day without extending their lead any further.
Yorkshire began the day on 312 for 7 and, despite a scare when Jordan Thompson edged onto his pad and just wide of the slips, they launched an early assault to secure another batting bonus point.
Thompson thumped Sanderson over extra cover for six, following it with another boundary to bring up his first half-century of the season as he and Matthew Revis plundered 42 from the first five overs.
The partnership reached 80 before the last three White Rose wickets went down in the space of nine balls, with Sanderson removing both Revis and Thompson leg-before and Leech castled by Rob Keogh for a second-ball duck.
Fernando almost made a dream start to his three-match stint with Yorkshire, his second delivery finding the edge of Ricardo Vasconcelos' bat but the ball whizzed past George Hill at first slip.
Vasconcelos settled down to share a lively opening stand of 56 with Emilio Gay, who struck a series of sweet off-side boundaries and caressed Hill's first delivery through midwicket for four more.
Two balls later, Gay was out for 32, prodding to second slip but - after a brief but bizarre stoppage when a swarm of wasps descended, prompting several fielders to fling themselves full-length on the turf - Northamptonshire reached lunch at 84 for 1.
However, Vasconcelos fell soon after the interval, with wicketkeeper Jonny Tattersall taking a skier to give Fernando his 300th first-class wicket and Yorkshire looked very much in the ascendancy when Revis claimed his first and second wickets of the season in quick succession.
Karun Nair, who never looked settled at the crease, was neatly taken at first slip off a rising delivery and George Bartlett departed for a duck, hanging the bat out to the jubilant Revis just four balls later.
Rob Keogh threatened to redress the balance with a bristling knock of 28 but, when he flicked Leech tamely into the hands of deep square leg, Northamptonshire's reliance on their skipper intensified.
Having lost both Lewis McManus and Justin Broad before tea, Procter needed Sanderson's shrewd display with the bat to shepherd his side past the follow-on target.
The 35-year-old looked accomplished for his 25 until he was trapped in his crease by Fernando, who also dismissed Siddharth Kaul to leave Northamptonshire nine down.
But last man White proved obdurate, blocking 14 deliveries before emerging from his shell to bludgeon Thompson for three quick fours as Procter progressed to his ton from 183 balls by shovelling Hill to the midwicket boundary.
The pair steered their side to a third batting bonus point before White holed out to long leg for 21, leaving Yorkshire to negotiate a single over in which Sanderson had Leech caught at fourth slip.
