United’s defence is notoriously porous and arguably cost them promotion last season, while it has been little better this time around, with a number of combinations failing to return a clean sheet prior to today.
But Grayson stumbled across the right formula this afternoon - although Greg Halford did go close to scoring for Pompey - and Pugh’s 14th-minute header, his first since returning to the club from Stoke after five years away, helped extend Leeds’ unbeaten run to four games.
“One or two of them were on their last warnings after last week,” Simon Grayson said of his players.
“I criticised the back four and I don’t normally do that, but I felt it was time that people took responsibility for what’s happened and they responded in the right manner.
“It was a good performance from us, I’m delighted that we kept a clean sheet for the first time this season.
“The players have taken on board what we have worked on this week.
“When they were called on the defenders defended and the goalkeeper made some good saves. We’re trying to get the right balance between attacking and defending and we’re delighted to keep the clean sheet.
“You have to be able to see stages of a game through and be determined and professional. We’ve probably been a bit naive, going gung-ho for the next goal, but we needed to be professional and we were.”
Leeds took a 14th-minute lead when Pugh raced in unmarked to head home from a deep corner from Robert Snodgrass.
Leeds dominated the opening half but Andy Lonergan went full-length to keep out a header from Greg Halford following a free-kick and the centre-back headed against the bar when the ball was chipped back across.
Lonergan also produced a smart save at the foot of his post to deny Halford from a fierce free-kick just before the break.
Kanu replaced Riise at the break to give Benjani a strike partner and Leeds began to look uncomfortable as Lawrence moved wide and attacked down the right.
Leeds responded by bringing on Becchio for Keogh in the 68th minute.
Forssell and Mika Vayrynen came on for the nervy closing stages for McCormack and Snodgrass.
Leeds were feeling the tension of having failed to score a second when on top, and Halford’s ability to get on the end of almost every ball played into their box added to their worries, with Darren O’Dea deflecting one of his efforts behind.
At the other end, substitute Mikael Forssell was denied a clinching second by Henderson’s flying save, but even though Lonergan had to scramble to tip over a Halford cross, Leeds held on without extending their advantage.
Leeds move up into the top half with the victory. They are 10th on 14 points, three points behind sixth-placed Hull City.
For the full report and reaction read Sports Monday, free inside Monday’s Yorkshire Post.