Chandimal, Nissanka, Asalanka put Sri Lanka 1-0 up despite Williams 100
The hosts chased down Zimbabwe's total with eight balls to spare thanks to several contributions with the bat
Sri Lanka 300 for 5 (Nissanka 75, Chandimal 75, Ngarava 3-56) beat Zimbabwe 296 for 9 (Williams 100, Kaitano 42, Karunaratne 3-69) by five wickets
Zimbabwe's batters gave their side a healthy chance. On a flat Pallekele track, the openers put on 80 off 88 balls - debutant Takudzwanashe Kaitano hitting 42, and Regis Chakabva going on to make 72 off 81. Then Sean Williams dominated the middle and late overs, hitting 100 off 87.
But although they made 296 for 9 - generally an excellent first innings score on Sri Lankan surfaces - the home side's top order had the measure of the target. They had three major contributors. Opener Pathum Nissanka hit the first half-century of his ODI career, making 75 off 71 to set the chase up. Then No. 4 Dinesh Chandimal and No. 5 Charith Asalanka took the baton, putting on a match-defining 132-run stand, hitting 75 off 91 and 71 off off 68 respectively. In the end, they got there with five wickets and eight balls to spare.
On a surface that was not particularly conducive to turn, the seamers of both teams made bigger contributions. For Sri Lanka, Chamika Karunaratne took 3 for 69 and Nuwan Pradeep claimed 2 for 54, both bowling their full quotas. Zimbabwe's standout was Richard Ngarava, who claimed 3 for 56 from nine overs. Blessing Muzarabani and Sikandar Raza claimed one wicket apiece.
In nine previous ODI innings, Nissanka's high score had been 24, but batting in his preferred opening position in this match, he was efficient in the Powerplay, finding boundaries through midwicket and through cover, as Sri Lanka cruised to 59 for 1 at the end of the 10 overs. He put on a 40-run partnership with Kusal Mendis, and 41 with Kamindu Mendis, but it was during his stand with Chandimal that Sri Lanka really gained the advantage, the pair making 66 together off 66 balls.
Nissanka continued to score heavily off errors of length, and struck at a run-a-ball more or less throughout his innings, reaching his maiden ODI fifty off the 49th delivery he faced. He was out in the 25th over, edging Sikandar Raza behind, though it did take a review to dislodge him.
Sri Lanka were a batter light in this game, with Karunaratne coming in at No. 7, but their next partnership made the game safe. Chandimal had begun slowly, as he often does in ODIs, hitting just 11 off his first 22 balls, but nurdled his way into a comfortable rhythm, and even before he struck his first boundary, off his 43rd ball, looked like he would play an innings of substance.
Where Nissanka had remained at close to a run-a-ball or better through the course of his innings, Chandimal was content to be less ambitious. He reached his half-century off his 64th delivery. Thanks to Asalanka scoring more quickly at the other end, Sri Lanka were cruising in their chase.
Asalanka himself had started with measure, but hit two fours and a six in the space of nine balls to get his strike rate around 100, and though he slowed slightly through the middle - Raza, Tendai Chatara, and Ngarava bowling nicely through the middle overs, Sri Lanka never seemed under particularly testing pressure, thanks to the singles both batters were squeezing out. Asalanka reached his fifty off the 57th ball he faced.
He accelerated a little after that, as Sri Lanka's required rate edged occasionally above a run-a-ball. He struck Ngarava for six over square leg to bring the equation down to five needed off the last 13 balls, then was hit on the pads and was trapped lbw. Dasun Shanaka and Karunaratne took the chase home in the next over.
Earlier, Zimbabwe had looked like they were headed to a total near 300 since the start of their innings, when Kaitano and Chakabva put on 80 together for the first wicket. Kaitano was the aggressor through much of that, finding five of his eight boundaries behind square. Chakabva also used the pace of the ball to score a substantial percentage of his runs, but also picked frequent singles and twos through cover and midwicket, against the spinners in particular, as he put on a 50-run partnership with Williams as well.
Williams' own innings was perhaps the best of the match, even if his first boundary was a lucky top edge for six off Nuwan Pradeep. He kept his run rate healthy via frequent singles and twos, but made sure to punish Sri Lanka's errors in line in particular. He reached his half-century off 52 balls, and upped the tempo in the death overs, although Zimbabwe will perhaps reflect they should have hit more than the 69 they managed in the last 10 overs, with six wickets still in hand.
Williams was especially severe on Karunaratne, whom he hit for two fours and a six in the 48th over. He got to his fifth career hundred in the next over, but Karunaratne dismissed him eventually, hitting his off stump as Williams heaved across the line. It was a heroic effort from the Zimbabwean, though in the end, not a match-winning one.
Andrew Fidel Fernando is ESPNcricinfo's Sri Lanka correspondent. @afidelf