Chandimal, Mathews thwart Pakistan victory bids
Sri Lankan batsman Dinesh Chandimal (left) plays a shot as Pakistan wicketkeeper Younis Khan looks on during their first Test match at the Sheikh Zayed Stadium in Abu Dhabi on January 3, 2014
Chandimal was unbeaten on 67 and Mathews 56 not out as Sri Lanka reached 285-4 at lunch, having an overall lead of 106 with six wickets intact after an extended two-and-a-half hour session.
The pair have so far added 99 for the unbroken fifth wicket.
They stand to frustrate Pakistan who had looked for early wickets after Sri Lanka were in a spot of bother when they resumed the day on 186-4.
But Chandimal and Mathews gave no chance to Pakistan as they batted in an unflappable manner to foil Pakistan's pace-cum-spin attack.
Chandimal glanced off-spinner Saeed Ajmal for his seventh boundary to reach his fifth Test half-century off 79 balls.
Mathews was more aggressive, hitting Ajmal for a six early in the day and then took a single off the same bowler to reach his 12th fifty -- second in the match following his 91 in Sri Lanka's first innings of 204.
Pakistan had made 383 in their first innings to gain a 179-run lead.
But both Mathews and Chandimal were not bothered at all and even the second new ball, taken at 249-4, failed to benefit Pakistan with a wicket.
Ajmal, who took 18 wickets in Pakistan's 1-0 win over Sri Lanka in United Arab Emirates in 2011, failed to pose any danger for the batsmen on a Sheikh Zayed Stadium pitch which had eased out for the batsmen.
Pacemen Junaid Khan had figures of 2-66 while Bilawal Bhatti took 2-90.