Dubai - Sri Lanka captain Upul Tharanga won the toss and sent Pakistan into bat in the first day-night international in Dubai on Friday.
Sri Lanka, who won the preceding two-match Test series 2-0, had spearhead Nuwan Perera ruled out from the one-day series with a hamstring injury and inducted Lahiru Gamage.
The remaining matches will be held in Abu Dhabi (October 16 and 18) and in Sharjah (October 20 and 23).
Three Twenty20 internationals will follow the ODIs, the last in Lahore on October 29.
Teams:
Pakistan
Sarfraz Ahmed (capt), Ahmed Shehzad, Fakhar Zaman, Mohammad Hafeez, Babar Azam, Shoaib Malik, Imad Wasim, Shahdab Khan, Hasan Ali, Rumman Raees, Junaid Khan
Sri Lanka
Upul Tharanga (capt), Dinesh Chandimal, Niroshan Dickwella, Lahiru Thirimanne, Kusal Mendis, Milinda Siriwardana, Thisara Perera, Lahiru Gamage, Suranga Lakmal, Akila Dananjaya, Jeffrey Vandersay
Umpires: Sundaram Ravi (IND) and Ahsan Raza (PAK)
Tv umpire: Richard Kettleborough (ENG)
ICC match referee: Andy Pycroft (ZIM)