Co-hosts New Zealand made it two wins from two at the World Cup, but they were made to work harder than expected for their three-wicket triumph over Scotland in Dunedin.
Trent Boult took two for 21 to be the pick of a blistering New Zealand attack, which left Scotland reeling on 12 for four early on and claimed four golden ducks.
Matt Machan (56 off 79 balls) and Richie Berrington (50 off 80 balls) helped Scotland eke out a total of 142, but the Kiwis still looked set to claim an easy win.
The Scots dug in, though, and Kane Williamson's 45-ball 38 was the top individual score for the Black Caps as they pushed hard and lost seven wickets before ultimately claiming the win with 151 balls remaining.
Cricket World Cup 2015: 10 young players to watch
Cricket World Cup 2015: 10 young players to watch
1/10 Usman Ghani, 18, Afghanistan
At just over 18 years old, Ghani is the youngest player at the tournament, but the attacking opener already has an ODI century to his name. If the Aghans are to spring a shock, much will depend on him getting them off to a good start.
2/10 Pat Cummins, 21, Australia
With his wonderful action and searing pace, Cummins burst onto the scene when he took seven wickets as an 18-year-old Test debutant against South Africa. Terrible injuries have prevented him from adding to his solitary Test cap, but now the stage is set for Cummins to re-establish himself as one of cricket's hottest talents.
3/10 Mominul Haque, 23, Bangladesh
A compact left-handed batsman, Haque will occupy the No.3 spot in the Bangladeshi batting order. He has already made 24 ODI appearances, but thus far has enjoyed more success in the longer format - in 12 Test appearances he has plundered almost 1200 runs at 63.05, with four centuries.
4/10 Jos Buttler, 24, England
One of the genuine box-office talents in the England squad, Buttler's 121 against Sri Lanka last summer was the most eye-catching innings of the season. His keeping needs work, but as a mid- to lower-order batsman he has the talent to change the course of a game in the blink of the eye.
5/10 Akshar Patel, 21, India
One of the few positives of India's disastrous recent Tri-Series with Australia and England was the consistency of Patel, who was miserly and probing with his tight left-arm spin. He enjoyed a superb 2014 IPL season with 16 wickets and an economy rate of just 6.22 for Kings XI Punjab.
6/10 George Dockrell, 22, Ireland
Despite having been a mainstay of the Ireland side since his debut in 2010, and with four county seasons at Somerset under his belt, Dockrell is still only 22. The canny spinner was named the ICC Associate Player of the Year in 2012, and he has been touted to follow Eoin Morgan into England colours.
7/10 Kane Williamson, 24, New Zealand
Williamson is the most consistent performer in a dangerous New Zealand batting line-up, his devastating recent form in all forms of cricket cementing his reputation as one of the most exciting, talented batsmen in world cricket. Having recently had his action cleared, he can now resume bowling his useful off-spin.
8/10 Ahmed Shehzad, 23, Pakistan
Despite his tender age, Shehzad boasts a wealth of experience, with over 50 ODI appearances and six centuries to his name. More of a classical, patient opener than a David Warner-esque pinch-hitter, he will lay the foundation from which Pakistan's big-hitting middle order can tee off.
9/10 Quinton de Kock, 22, South Africa
Since making his debut just after his 20th birthday, De Kock has been an aggressive, punchy performer at the top of the South African order, plundering six hundreds in just 36 matches. A tidy gloveman, who by taking over keeping duties has allowed AB De Villiers to focus on his batting, to devastating effect.
10/10 Tendai Chatara, 23, Zimbabwe
An athletic opening bowler with a curious, idiosyncratic action, Chatara takes the ball away from the right-hander at decent pace and is Zimbabwe's key strike bowler. His maiden Test five-wicket haul set up a famous victory over Pakistan in 2013.
Hopes will remain high that Scotland can win their first-ever World Cup match at this year's tournament, but the in-form Black Caps showed early signs they were not going to be caught short at the University Oval.
The Scots, who beat Ireland and pushed West Indies close in the warm-up matches, got off to the worst possible start and slumped to 12 for four after just 4.2 overs.
New Zealand, who named an unchanged side from their opening 98-run win over Sri Lanka, won the toss and elected to field, with that decision paying immediate dividends as Boult and Tim Southee wreaked early havoc.
Boult drew first blood, claiming two wickets in two balls as Calum Macleod and Hamish Gardiner both departed for golden ducks at the start of the second over.
Not to be outdone, Southee replicated Boult's efforts two overs later as Kyle Coetzer (one) departed after finding Grant Elliott at short mid-wicket and then Scots skipper Preston Mommsen walked straight after for a first-ball duck.
A 97-run fifth-wicket partnership between Machan and Berrington steadied the ship for Scotland, but the rest of their batting order fell away as New Zealand's red-hot attack wrapped their innings up in 36.2 overs.
Machan brought up an impressive 71-ball fifty around the halfway point of Scotland's allotted overs, with Berrington smashing a six over long-on from Daniel Vettori afterwards in celebration.
But Corey Anderson ended their stand in the 28th over, as Machan (56) top-edged an attempted pull to Brendon McCullum at mid-on, and then he got Berrington out two overs later, just after the 27-year-old claimed his seventh ODI fifty to leave the Scots on 117 for six.
Anderson and Vettori then mopped up the tail between them, taking three wickets in total apiece, with Scotland's innings ending how it started as Vettori caught Iain Wardlaw in front for a golden duck. The final four wickets fell for just 25 runs.
Martin Guptill (17) was a man in a hurry as New Zealand looked to complete their chase of 143 at breakneck speed.
The Kiwi opener smashed two fours in as many overs and then found back-to-back boundaries at the start of the third over, before his ambition got the better of him and his attempted lift over long off was edged behind to Matthew Cross.
Black Caps skipper McCullum (15) walked to the same combination at the end of the seventh over as Scotland began to dig in, leaving New Zealand on 63 for two at lunch.
The expected onslaught from the co-hosts was slow in coming and Ross Taylor was out for nine in the second over after lunch, before a fourth-wicket stand of 40 from Williamson and Elliott anchored the Black Caps' innings.
Williamson (38) became the first of three Josh Davey victims in the 18th over and Elliott (29) fell soon after to leave New Zealand on 117 for five, needing 26 off 29 overs to claim the win.
With New Zealand continuing to force the issue Davey made things interesting by claiming two wickets in three balls as Anderson (seven) and Luke Ronchi (12) both fell in quick succession as the co-hosts finished the 24th over five runs short with three wickets left.
Vettori finally wrapped things up for the Black Caps in the next over as he unconvincingly top-edged through the slip region for four to take New Zealand to 146 with just over half their allotted overs remaining.