The hosts ended the day on 222 for two in their second innings to leave number one-ranked Test side England facing a third defeat in the three-Test series unless the struggling tourists suddenly strike form.
The England bowlers labored as an unbeaten 194-run partnership between Younus (115 not out) and Azhar Ali threatened to take the match away from Andrew Strauss's men, who must bat last having crumbled in a similar position in the second Test in Abu Dhabi.
"I was very upset with the way I got out in the first innings. I was determined not to repeat this," Younus told a news conference.
"I just thought I should do something that no one else has done in this series. No one has made a century so far." Younus's 20th Test century was studded with 11 fours and one six and came of 195 balls as the 34-year old batsman skillfully worked through England's pace and spin attack.
"Whatever we can get tomorrow would be good and a strong target. I was lucky today and the ball kept coming on to the bat. Also, I didn't make any mistakes," he added.
"The first session tomorrow will be crucial. I think England tried their best but at the moment we have an edge over them. They need some more luck and aggression and they may get through." SERIOUS GUTS Azhar eased to his half century and was unbeaten on 75 off 246 balls at stumps.
England's Alastair Cook acknowledged that a defeat was the most likely result.
"It will take some serious guts for us to drag ourselves out of this," he said.
"We tried a lot of things. But Younus took the attack to us. He didn't let the bowlers settle to any kind of rhythm. It is very frustrating...we have not played to the standards that we know we can (all series)." The post-lunch run-scoring was in stark contrast to what has been seen in the match and series so far.
This Test, being played at the Dubai International Cricket Stadium, had already seen 22 wickets fall in less than two days.
Six wickets tumbled in the morning session.
Both Pakistani openers were dismissed cheaply. James Anderson struck first, dismissing Taufeeq Umar (6) for the second time in the match, this time caught at slip.
Left-arm spinner Monty Panesar trapped Mohammad Hafeez lbw (21) on the sweep.
Earlier, Pakistan bowled out England's lower order to trail by 42 runs as the touring party made 141 in reply to Pakistan's first innings of 99.
Abdur Rehman's five-wicket haul ensured a half century by captain Strauss (56) only resulted in a modest lead for England.
Pakistan, playing their home matches in Dubai due to security reasons, launched their spinners into the attack and they found immediate success.
Rehman, enjoying a purple patch of form, got his fourth wicket in the match when he dislodged the leg stump of nightwatchman Anderson (4) in the first over.
A doosra by Saeed Ajmal rapped Stuart Broad (4) on the pad and was given out on review. Rehman got his fifth wicket as Strauss stepped out to heave one over the park, only to be stumped.
Graeme Swann added a quick 16 runs but was soon caught by Rehman following a lofted shot off Ajmal.
