Glamorgan 221 (B Root 51, Bess 4-25, Moriarty 4-74) and 171 for 3 (Northeast 46*, Ingram 43*) trail Yorkshire 519 for 7 dec (Bean 173, J Root 156, Brook 65) by 127 runs
Joe Root completed a superb day three 156 as Yorkshire pushed for a Vitality County Championship victory over Glamorgan at Headingley.
Root followed Fin Bean's lead, the opener who scored his first century of the season late on day two and went on to make 173 in Yorkshire's imposing first-innings 519 for seven declared.
Glamorgan then reached close on 171 for three from 60 overs in their second innings, with unbeaten Sam Northeast and Colin Ingram approaching half-centuries. The visitors trail by 127.
Root, 92 overnight, posted a classy century - his second in as many Division Two games - and shared 265 for the third wicket with Bean through until mid-morning as the hosts replied to a 221 total on a used pitch.
Harry Brook then piled further pressure on the beleaguered visiting attack with two sixes in 65, though he fell to one-time England Test leg-spinner Mason Crane to spark the declaration in the first half of the afternoon.
Crane finished with a consolatory five for 152 from 23.1 overs.
Despite batting on a deteriorating pitch, Yorkshire's innings advanced at a rate of just over 5.5 runs per over. They were helped out as a depleted Glamorgan attack erred with the ball.
Last year, Glamorgan had much the better of an early season draw here when Australian seamer Michael Neser took a hat-trick. But this attack looks very different to the one which took the field exactly 12 months ago.
Neser has not returned to the club this season, while fellow seamer Timm van der Gugten is injured. Another quick Harry Podmore is also sidelined and all-rounder Dan Douthwaite rested.
Bean's highest first-class score came as he batted with more aggression than usual, the left-handed opener making a conscious effort to put pressure on the bowlers.
In January, the 22-year-old had spent time in India working on batting against spin as part of an England Lions batting camp.
On this evidence, it was 10 days well spent given the spinning nature of this pitch, him hitting 24 fours and five sixes in 173 balls. Four of his five sixes were hit over long-on or straight off spin.
For Root, he backed up last weekend's 119 in the draw against Derbyshire with a typically classy innings. He reached this century off 100 balls in the opening 15 minutes of play and went on to hit 21 fours in 165 balls.
Bean, having been dropped at first slip on his overnight 140, was the first wicket to fall, bowled playing back to Crane, before Root was trapped lbw by seamer James Harris.
Crane is on a season-long loan from Hampshire in a bid to get more regular cricket.
He took four of his five wickets on day three and will be most pleased that his last three wickets came at a cost of only one run, including Jonny Tattersall stumped for a confident 55 and Brook caught at backward point. The hosts declared immediately.
Glamorgan's openers Eddie Byrom and Billy Root started their second innings brightly, sharing 56 inside 18 overs.
But both fell either side of tea as the score slipped to 72 for two. Root played on to Dan Moriarty's left-arm spin for 35 before Byrom was caught at deep square-leg on the sweep against Dom Bess's off-spin.
Kiran Carlson was then unfortunate to be run out having struck a drive against Bess against Joe Root at silly point. The ball ricocheted back to wicketkeeper Tattersall, who removed the bails with the batter scrambling to make his ground - 93 for three.
Thankfully for the visitors, Northeast and Ingram steadied the ship and held firm for the rest of the day and will resume on 46 and 43 respectively.
They will, however, likely need to significantly build on their 78-run partnership to give Glamorgan a chance of avoiding defeat.
