Sri Lanka will take their place alongside the region's elite nations in 2011 after Chamara Vithanage's last gasp try secured a 23-16 victory over Singapore and with it the HSBC Asian 5 Nations Division I title for the first time.
The third seeds turned in a comprehensive performance in wet and humid conditions at Yio Chu Kang Stadium to deny hosts Singapore an immediate return to the Top 5 alongside the likes of Japan, Korea, Hong Kong and Kazakhstan.
Singapore, the top seeds, did not look entirely comfortable, particularly in the back three with a slippery ball and clever kicking from Sri Lanka kept their hosts on the back foot and somewhat negated their superior size in the pack.
The loss of captain Matt Ryan to injury in the 20th minute did not help Singapore's cause, having already lost usual captain Jonathon Lee in a trial match a fortnight earlier in Australia.
Singapore did, though, take an early 6-0 lead with two penalties from fly half Tom Burns in the first quarter as the hosts capitalized on the sin-binning of Sri Lanka scrum half Roshan Weeraratne in the sixth minute.
Saliya Kumara and Weeraratne pulled Sri Lanka level with a penalty and drop goal respectively to send the sides in to the changing rooms all square at half time before an enthusiastic crowd of nearly 2,000.
Sri Lanka's final act
Full back Kumara edged Sri Lanka into the lead for the first time within three minutes of the restart, before Weeraratne made amends for his earlier sin-binning by finishing of a flowing move to score the first try of the match.
Trailing 16-6 with half an hour remaining, Singapore gradually began to find their feet and exert periods of pressure and plenty of possession, getting their reward when wing Desmond Wee tiptoed down the touchline to score their only try.
Sri Lanka gave away another penalty to allow Burns to tie the score once more to leave the match up for grabs with the final quarter to play, resulting in end to end play with the volume and fervour of the crowd growing by the minute.
Then with extra time seemingly looming to decide the Division I champion, Sri Lanka broke through the Singapore Lions' defence on the last play of the match for centre Vithanage charging over in the corner to snatch victory.
The celebrations could begin with Sri Lanka safe in the knowledge they would be the seventh team to grace the Top 5 with Arabian Gulf and Singapore also having joined Asia's traditional leading lights.
Exactly who Sri Lanka will replace is not yet known, with the Top 5 kicking off at the weekend with 2009 runners up Kazakhstan welcoming Arabian Gulf to Almaty and the massive encounter between Hong Kong and Korea.
Japan, the favourites to secure a third successive title and therefore Asia's place at Rugby World Cup 2011 in New Zealand, have a bye on the opening day of a competition which spans five consecutive weekends.
Survival target realised
Malaysia, meanwhile, bounced back from the disappointment of a 22-20 loss to Singapore on Wednesday in style by retaining their place in Division I with a 35-8 victory against a youthful Chinese Taipei outfit.
Chinese Taipei, who blooded 12 new players in their 37-7 loss to Sri Lanka, produced a much-improved performance but had no answer to a Malaysian backline featuring four Fijian-born players.
Three of these players crossed for tries in the victory, wing Nacani Seniu scoring a brace with centre Timoci Nacokula and full back Isoa Turuva helping the 2009 Division II champions to preserve their position in the competition's second tier.
Chinese Taipei, whose only try came from flanker Chen Kuo Lun, will drop down to Division II in 2011, with their place being taken by that tier's winner be it top seeds Thailand, China, India or the Philippines.
The local fans were also treated to an Asian 5 Nations milestone with the first ever women's international match played as a curtain raiser to an event with Singapore hosting their Malaysian counterparts.
Singapore scored first to take a 5-0 lead into half time, but two quick-fire tries saw Malaysia establish a 10-5 advantage before the match had to be abandoned as a result of a lightning storm.
Sri Lanka will play in the Top 5 next year with Asia's elite - Photo: Adzni Yusof