While Singapore registered an emphatic 40-run win over Malaysia in Klang, Nepal ended Thailand's unbeaten start after a 140-run rout under the Duckworth/Lewis method in the second of two matches at the Bayuemas Oval.
Nepal top the standings on six points ahead of Singapore on net run-rate while Thailand slipped to third with five points from four matches, two ahead of fourth-placed Malaysia. Only the top three at the end of the round-robin tournament advance to the Asia Regional Finals.
In a bottom-of-the-table clash between two winless teams, Myanmar beat China by eight wickets in Bangi to sit in sixth spot on two points, trailing Bhutan on net run-rate.
Malaysia's hopes of finishing third at least is hanging by a thread after Singapore's player-of-the-match Anantha Krishna bagged four wickets for 14 runs to dismiss the hosts for 105 in 20 overs in response to Singapore's 145/9.
Chaminda Ruwan Kumarage found the boundary seven times in scoring 41 runs to steady the ship for Singapore after they were reduced to 34/2 when Malaysia's Syed Aziz Syed Mubarak (2/21) removed openers Aritra Dutta and Surendran Chandramohan.
Manpreet Singh and (22) and Janak Prakash (20) added valuable contributions to the total as Malaysia's Syazrul EzatIdrus and Syed Aziz conceded a combined 27 runs in the last two overs.
Malaysia suffered an early blow when Amjad Mahboob removed Shafiq Sharif and Suhan Alagaratnam with successive deliveries in the second over with just seven runs on the board.
Captain Ahmad Faiz Mohammed Noor, who promoted himself up the order to No 2, was next to go after scoring 25 with five fours and despite Virandeep Singh making 39 off 41 balls, Malaysia never looked like reaching their target.
Singapore captain Chetan Suryawanshi was pleased with his team's performance but cautioned that the job was not done with three matches still to come.
"The pitch was very dry and we knew it was going to turn a lot and the first six overs was very crucial," said Suryawanshi after Singapore conceded just nine boundaries in all and not a single six.
"So it was clear to the batsmen that we have to capitalise and to the bowlers that we've got to contain in those overs. Both departments did well.
"The bowlers did well to take early wickets and squeeze them in the end, especially on this wicket. Our hard work has paid off this week but we've still got three games to play against Bhutan, Thailand and Nepal. We will take it one game at a time."
The defeat leaves Malaysia languishing in fourth place, two points behind Thailand, and needing to win their remaining two games against Myanmar and China to stand a chance of advancing to the regional finals.
Thailand's last two games are against Singapore and Myanmar but their defeat to Nepal offers hope to Malaysia of squeezing through on net run-rate.
Nepal meant business in setting the tournament's highest total of 172-7 as Karan KC plundered 21 runs off Nicholas Janes in the final over, including three consecutive sixes, in compiling an unbeaten 40.
Karan later returned to claim three wickets for two runs to take the man-of-the-match honour as shell-shocked Thailand collapsed to 18/9 after 8.5 overs before play was called off due to rain.
A reshuffled line-up saw Nepal out of the blocks quickly when put in to bat by Thailand as Anil Kumar Shah (25), Binod Bhandari (15), Sharad Vesawkar (34) and Dipendra Singh Airee (30) quickly set about putting runs on the board.
But Thailand struck back in the middle of the innings with four wickets for the addition of 15 runs as Payuputh Sungnard finished with four for 21 before Karan's final flourish in a 44-run stand for the eighth wicket with Sompal Kami.
Thailand could not have made a worst start to their chase after losing Md Shafiqul Haque and Daniel Jacobs after eight balls with just one run scored.
With dark clouds gathering over the ground, Nepal were in a hurry to wrap up the win and Thailand were soon 6/3 when Janes was trapped leg-before by Sandeep Lamichhane.
A day after taking five wickets against Malaysia, Lamichhane again ended with five for eight including three scalps in the space of four deliveries in the eighth over to take his tournament tally to 14 wickets.
"It has been a good three games but we take nothing for granted and we go out there to do our best. I'm glad everybody has put in that effort" said Nepal captain Paras Khadka.
"At the end of the first innings, the weather looked a bit sketchy so we wanted to finish off the five overs as quickly as possible just to get a result under D/L. The bowlers responded splendidly."
Myanmar secured their first win of the tournament at the UKM Oval after overhauling China's 48 all out to reach 49/2 in 7.5 overs.
Htet Lin Aung claimed four for 11 from four overs as China were bowled out in 15.2 overs before Ko Ko Lin Thu (18) and Khin Aye, with an unbeaten 15, steered Myanmar to their target.
The tournament takes a break on Monday and resumes on Tuesday when Singapore face Thailand and Malaysia play Myanmar at Bayuemas while Nepal take on Bhutan in Bangi.
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