Vietnam cut the deficit with Indonesia early Thursday, after four more golds in pencak silat -- an Indonesian martial art -- took them to 62 first places and stretched their lead over third placed Thailand.
The Thais, 2009 SEA Games table-toppers, have stalled after bouncing back from a disappointing start to the 26th edition of the Games with a strong showing in the headline athletics events and have 54 golds.
Indonesia's footballers are preparing to take on defending champions Malaysia Thursday, with home fans demanding a win over their arch-rivals as they eye gold in the event for the first time in two decades.
The hosts, on 90 golds by early Thursday, play neighbouring Malaysia in the final group game having already qualified for the semi-finals of the under-23 tournament after three wins.
Malaysia have one foot in the semis and could be through by the time the game kicks off if Singapore fail to beat Thailand.
But both coaches have said the match -- in front of an expected 90,000 sell-out crowd -- is not a dead rubber with national pride at stake and a tie against surprise package Myanmar or the free-scoring Vietnam awaiting.
Coach Rahmad Darmawan told the Jakarta Globe that he harboured no fears over his opponents in the next round.
"Vietnam is an aggressive attacking team with good organisation. Burma (Myanmar) is very good at defending their turf and their players have been playing with great fighting spirit," he was quoted as saying.
"Our focus now is to win against Malaysia."
Malaysia's coach has pledged to go for a win, vowing his players would go all out to upset the unbeaten hosts as they chase a title defence -- Malaysia beat Vietnam in the 2009 Games final.
"If we are to become champions, then this is the match we have to win," Ong Kim Swee was quoted as saying by the Malaysian Star newspaper.
"A point should be sufficient for us but I want the boys to show character. The Indonesian hurdle is the biggest obstacle before us. Once we get past it, we should be favourites for the gold."
The biennial SEA Games sees 11 nations compete for bragging rights with hundreds of gold medals up for grabs.
What the stars mean:
★ Poor ★ ★ Promising ★★★ Good ★★★★ Very good ★★★★★ Exceptional