Sri Lanka, who added 101 runs losing a single wicket in the first session of the day, continued to dominate despite losing wickets in the second session.
Karunaratne became the first Sri Lanka opener to record three Test centuries in a calendar year since 2012, only Proteas opener Dean Elgar has scored more hundreds this year with his tally of five. "Normally the Pakistan batters really struggle against the left-arm spinners".
Karunaratne missed out on a maiden Test double-century when he played on to a delivery from Wahab Riaz, who earlier took six attempts to bowl the fifth ball of an over before finally getting his run-up right. The last of the T20Is is scheduled to be played in Lahore.
Pakistan have never lost a Test series in the UAE since making it their adopted home in 2010.
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With home players caught too far forward, Carrasco calmly slotted the ball past goalkeeper Asmir Begovic. Already qualified from Europe Group H, Belgium fielded a strong squad and twice came from behind.
As Lahiru Thirimanne continues to suffer from back stiffness, Sadeera Samarawickrama will most likely get the opportunity to make his test debut in the day/night test later today.
Yasir Shah struck in the 23rd over as he got Silva caught by captain Sarfraz Ahmed to bring a temporary respite to the Pakistan camp.
Leg-spinner Yasir Shah was the pick of bowlers with 2-90 while Amir returned figures of 1-59.
Pakistan still have plenty of work to do to if they are to level their two-Test series with Sri Lanka after the tourists racked up 482 on day two thanks to Dimuth Karunaratne's brilliant 196. Pakistan will also hope spearhead Mohammad Amir returns to form with the pink ball after going wicketless in the first Test. Debutant Haris Sohail provided a positive in the batting after scores of 76 and 34, while Azhar Ali hit 85. That said, it will be interesting to see if Sri Lanka face any difficulties in adapting to the nuances of a day-night Test.