Dasun Shanaka hammered the fastest half-century by a Sri Lankan in T20Is as the co-hosts thrashed Oman by 105 runs at the World Cup on Thursday in Pallekele for their second win in Group B.

The 2014 champions piled up 225-5, the highest total of the tournament, before restricting an outclassed Oman to 120-9.

The 43-year-old Mohammad Nadeem waged a lone battle for Oman, compiling an unbeaten 53 to become the oldest player to score a fifty in T20 World Cups.

Having promoted himself up the order and under pressure to deliver, Sri Lanka skipper Shanaka smashed a 19-ball half-century.

It has been a bruising few months for the out-of-form Shanaka since reclaiming the captaincy late last year.

But on a batting-friendly pitch he smacked the Oman bowlers to all corners of the park, peppering the stands with five sixes and two fours.

Before that, Pavan Rathnayake and Kusal Mendis laid the foundation as the pair each posted fluent half-centuries, stitching together a 94-run stand for the third wicket.

“After the last game, the manner in which I was dismissed, it was disappointing,” Rathnayake said.

“I wanted to make it count today, and glad I was able to score a half-century. Pallekele is always good for batting and I enjoyed the outing. More importantly, the team is one more step closer to the second round.”

Once the platform was set, Kamindu Mendis applied the finishing touches.

Fresh from his match-turning cameo in the win over Ireland, the left-hander scored an unbeaten 19 off just seven deliveries, striking one four and two sixes.

Oman were never really in the game as they fell to a second defeat at the tournament.

Sri Lanka spinner Maheesh Theekshana shared the new ball with Dushmantha Chameera and they accounted for two wickets apiece.

“We are a better side than what we showed today,” said Nadeem.

“On this pitch we should have kept them for 180, but 225 was too much. We have had two bad games now and it feels disappointing. “