Sri Lanka 155 for 4 (Dilshan 83*, Mathews 21*) beat Afghanistan 153 for 7 (Stanikzai 62, Shenwari 31, Thisara 3-33) by six wickets
Scorecard and ball-by-ball details

A calmly compiled 56-ball 83 from Tillakaratne Dilshan steered Sri Lanka to a heart-rate-steadying six-wicket win in their opening match of the World T20, but not before Afghanistan reminded them and the rest of Group 1 that they belonged in the Super 10s.

With the bat, Afghanistan recovered brilliantly from a poor start, scoring 106 runs in their last ten overs to set a challenging target of 154. They bowled with skill and intelligence to claw back into the match after Dilshan and Dinesh Chandimal had given Sri Lanka a bright start: 41 for 0 in five overs.

In the end, it was only Afghanistan's fielding that proved to be of less-than-elite standard, with three basic errors in the deep giving a jittery Sri Lankan batting unit valuable breathing room.

First, in the 14th over, Karim Sadiq failed to get his body behind a regulation stop at deep midwicket. Then, in the 16th, Dawlat Zadran made the same mistake at deep backward square leg. The third misfield came from the substitute fielder Gulbadin Naib, who dived to his left at third man, got a meaty hand to the ball, and only ended up pushing it past the rope. Sri Lanka should have only got three runs from those three balls; they ended up getting 12.

Sri Lanka would have appreciated the help, for barring Dilshan, their top order showed itself to be decidedly wobbly.

Mohammad Nabi's introduction in the sixth over exposed the wobbliness. Sri Lanka were going along comfortably when Chandimal stepped out and aimed a heave over the leg side. The ball turned a little further than expected and popped off the inside half of his bat straight to midwicket. Lahiru Thirimanne, back in Sri Lanka's T20 side for the first time since May 2014, showed why he may have been out of the side for so long, playing only three scoring shots in 12 balls before inside-edging an attempted cover drive off the legspinner Rashid Khan onto his stumps.

At the other end, like Mahela Jayawardene did during the two sides' 50-over World Cup meeting last year, Dilshan provided the experienced head that guided Sri Lanka through this troubled period. He had started in his usual manner, hitting consecutive sixes off Dawlat Zadran - the second with a trademark scoop over his own head - and swatting Hamid Hassan for successive fours over midwicket, but did not take too many chances against the spinners. But he still scored freely against them, taking the singles on offer, putting away the bad ball, and running faster than every other 39-year-old on the planet to pick up a couple of twos to the leg-side gaps.

There were a couple more nervy moments, courtesy the run-outs of Thisara Perera and Chamara Kapugedera, but the cool heads of Dilshan and Angelo Mathews, helped along by Afghanistan's sloppy fielding, took Sri Lanka home with seven balls remaining.

Having only faced Scotland, Hong Kong and Zimbabwe so far, it took Afghanistan a while to come to terms with the quality of Sri Lanka's attack. Mohammad Shahzad, unusually subdued early on, tried to break free of the shackles in the third over and clouted Angelo Mathews to the straight boundary before top-edging a pull to mid-on the next ball. Apart from a couple of sweetly-timed leg-side flicks, Noor Ali Zadran struggled for tempo, and was bowled around his legs by Rangana Herath after adding 32 off 32 balls with Asghar Stanikzai.

Herath settled into a beautiful rhythm, mixing his pace and trajectory cleverly, and the run rate plummeted as Sadiq and Nabi soon followed Noor to the pavilion.

Stanikzai had moved to 18 off 23 balls when he made an abrupt change of gear against Milinda Siriwardana's left-arm spin, launching him for successive sixes in the 13th over, before slog-sweeping Herath for another six in the 15th over, with a helping hand from a butter-fingered Thirimanne in the deep. At the other end, Samiullah Shenwari hit two fours and a six - including a reverse-swat off Perera that left the batsman on his backside - in successive overs before holing out to long-off.

Stanikzai and Shenwari, the heroes of Afghanistan's ODI win over Bangladesh in 2014, had put on 61 in 33 balls. It clearly rattled Sri Lanka, and Mathews dropped Stanikzai at cover immediately after Shenwari's dismissal. It was a sitter, and Stanikzai, at 44 at that point, struck two more fours and a six to move to his highest T20I score before falling at the end of the 19th over.

Afghanistan were by no means done. Najibullah Zadran, a specialist batsman, had only batted once in the tournament so far, and was slotted to come in at No, 8, but found his namesake Dawlat promoted above him instead. When Najibullah finally did come out, there were only three balls left in Afghanistan's innings. No problem. Swinging freely through the line like a young Yuvraj Singh, Najibullah lofted Nuwan Kulasekara for a six over extra cover first ball, and then flat-batted him in the same direction for a four next ball.

Karthik Krishnaswamy is a senior sub-editor at ESPNcricinfo