Afghanistan, Ireland, Zimbabwe and Bangladesh failed to spring a surprise before bowing out in the group stage.
With the Super Eights split into two groups, Group 2 looks marginally more challenging, with South Africa, Australia and former champions India and Pakistan in the chase for semifinal berths.
Host Sri Lanka takes on New Zealand on Thursday in Group 1, which includes defending champion England and West Indies, who meet in a double-header at Pallekele International Stadium.
All four Group 2 teams won their first-round matches while West Indies is the only team to progress without a victory, doing so on superior run-rate after its matches against Australia (loss) and Ireland (abandoned) were affected by rain.
The three subcontinent teams – India, Pakistan and Sri Lanka – will be relying heavily on their spinners.
Sri Lanka finger spinner Ajantha Mendis broke his own world record with staggering figures of 6-8 against Zimbabwe.
Offspinner Harbhajan Singh returned after a year out with an impressive four-wicket haul against England as India shot out the defending champ for only 80 after posting 170-4.
Flow of runs
Pakistan offspinner Saeed Ajmal also took four wickets against New Zealand and denied the Black Caps a victory with two wickets in the last over.
The Asian teams' pacemen struggled to curtail the flow of runs, but there was no such headache for South Africa, New Zealand and England.
South Africa's Dale Steyn and Morne Morkel bowled with lot of verve and Sri Lanka lost its rain-curtailed seven-overs-a-side match against the Proteas by 32 runs.
New Zealand's Kyle Mills and Tim Southee knocked over Bangladesh's top order with six wickets between them after Brendon McCullum smashed a best-ever T20 innings of 123 off 72 balls.
New Zealand has the advantage of knowing the conditions well at Pallekele as it played both of its first-round matches there.
Kiwis skipper Ross Taylor hoped his batsmen will also show as much aggression against the Sri Lanka spinners as they did against Bangladesh.
"The main message is to be aggressive and not let them settle," Taylor said. "The two games that we've had against Pakistan and Bangladesh, there was one short boundary and one big boundary … if there is a short boundary then we need to attack that."
A host team has yet to win the World Twenty20, but Sri Lanka hopes to end that jinx thanks to Mendis, Lasith Malinga, captain Mahela Jayawardene, Tillakaratne Dilshan and Kumar Sangakkara.
Mendis missed the rain-shortened game against South Africa due to a side strain during his record-breaking performance against Zimbabwe. Coach Graham Ford said it would be a setback if Mendis could not recover for Thursday's match.
"With the way he bowled and the x-factor he brings, it would be a big blow," Ford said. "In T20 cricket you want guys who can win matches on their own and he's one of those guys."
Led by Luke Wright's brilliant 99, England's top order flourished against the mediocre bowling attack of Afghanistan before it hit rock bottom against Indian spinners at Colombo.
There will be no letup for them in the Super Eights, where they will face the likes of Mendis and West Indies' offspinner Sunil Narine.
"I think it's important for the batsmen to get back into the nets and feel hitting the ball again. It's all a state of mind, getting yourself back into a positive frame," England captain Stuart Broad said.
West Indies' batting reputation precedes it, so much of its hopes rest on Narine helping to restrict opponents.
"Sunil is our trump card, he has done well for us in this format and hopefully he could have a big impact on the English batting lineup," captain Darren Sammy said. "We definitely look to bowl spin against them, but we have quality seam bowlers up front in Fidel [Edwards] and [Ravi] Rampaul."
Pakistan has problems with its pacemen, but its top order batsmen all have showed decent form, with Imran Nazir smashing 72 against Bangladesh and Nasir Jamshed scoring 56 against New Zealand. Captain Mohammad Hafeez also played useful knocks of 43 and 45.
Pakistan struggles when chasing a target. Although it successfully chased down 176 on Tuesday against Bangladesh for the loss of only two wickets, the competition is much stronger from here on.
"In the pace bowling department there's probably a bit of an issue with the implementation of the basics," Hafeez said. "Mohammad Akram [the bowling coach] is working hard at this, but sometimes things just don't work out." – Sapa-AP