Singapore slipped to their lowest-ever spot in the latest Fifa rankings as the Lions fell 16 places from September's 155th spot.
This is also Singapore's all-time lowest Fifa ranking with their previous worst of 165th coming in June 2013. Malaysia have also slipped down the ladder six places from their previous position of 158 but have managed to stay above the Lions.
The drop in rankings comes after V Sundramoorthy's side's recent goalless draw against Ong Kim Swee's Malaysian on October 7 which was followed by a 2-0 defeat to Hong Kong in their international friendlies. The 51-year-old coach, who replaced former in-charge Bernd Stange earlier this year, has been struggling to produce ideal results with the national team.
Since leading his side to a win in his first game in June 2016 against Myanmar, Sundram has suffered a winless streak, which has now extended to five games, out of which four have been defeats.
Sundram would definitely want his side to do some damage control in the upcoming AFF Suzuki Cup, which will be played in November. Singapore will reportedly play three more friendlies, of which one will be at the National Stadium, before the eight-team tournament.
The Lions are drawn in Group A along with co-hosts Philippines, who are also the top-ranked (124) Southeast Asian nation, Thailand and Indonesia. Kim Swee's team will play Myanmar, Vietnam and Qualification winners in Group B.
Meanwhile, Argentina continue to be the top-ranked team from 209 countries in the list. Brazil, Germany, Belgium and Colombia occupy the top-five spots while 2016 European Championship runners-up have climbed a spot to seventh and winners Portugal have slipped to eighth.
England, who won two of their three recent 2018 Fifa World Cup Qualifier matches, have retained 12th spot behind Spain and Wales.