UPDATE 2-Cricket-Yousuf guides Pakistan to 50-run lead

GALLE, Sri Lanka, July 5 (Reuters) - Mohammad Yousuf celebrated his return to international cricket with a century on Sunday to give Pakistan a 50-run lead on the second day of a delicately balanced first test against Sri Lanka.

At the close, Sri Lanka were nought for no wicket in their second innings after Pakistan had been dismissed for 342.

Yousuf, recalled to the national team after his ban for playing in the unofficial Indian Cricket League was lifted, scored 112 from 185 balls before he was run out. His innings included 10 boundaries and was his 24th test century in a 80-test career.

The 34-year-old right-hander was supported by Misbah ul-Haq, who scored 56 and helped add 139 runs for the fifth wicket, the most productive partnership of the match to date.

Resuming the day on 15 for two, Younus Khan (25) and Abdur Rauf (31) started Pakistan's recovery after the loss of their openers on Saturday evening with a 50-run stand for the third wicket.

However, paceman Nuwan Kulasekara (4-70), the pick of the Sri Lanka bowlers, claimed the first victim of the day with the dismissal of nightwatchman Rauf, who edged to wicket-keeper Tillakaratne Dilshan.

All-rounder Angelo Mathews then snared a wicket in his first over in test cricket, finding the outside edge of Younus's bat with an outswinger to dismiss the Pakistan skipper.

Yousuf steadied the innings in partnership with Misbah either side of the lunch interval.

The tourists appeared to enjoy some good fortune when umpire umpire Darryl Harper rejected a confident bat-pad appeal off left-arm spinner Rangana Herath when Yousuf was on 57.