Victory saw Chile go level on 21 points with third-placed Ecuador, who they trail by goal difference. Chile are five points clear of fifth-placed Uruguay.
The top four teams automatically qualify for Brazil, with the fifth placed team facing a play-off against their Asian counterpart.
South Korea edged a tense encounter against Uzbekistan and Australia finally hit form with a 4-0 win over Jordan as the regional giants took big strides toward next year’s World Cup on Tuesday.
South Korea’s 1-0 victory, courtesy of a first-half own-goal, puts them one point clear in Group A ahead of Iran, who outclassed bottom side Lebanon 4-0 in Tehran.
It all sets things up for a thrilling denouement next week, with the South Korea hosting Iran in their final game in what should be a highly charged atmosphere in Ulsan.
Third-placed Uzbekistan, still capable of making history as the first Central Asian country to reach the World Cup, are at home to 2022 World Cup hosts Qatar, who are out of contention.
Only the top two teams in Asia’s two final qualifying groups win an automatic spot, with the third-placed countries entering a play-off. Group B winners Japan are the only team to book their ticket to Brazil so far.
Meanwhile, Australia eased their jitters after a lackluster campaign with a win that leaves them in Group B’s second automatic qualifying spot ahead of their final game at home to Iraq next week.
At Melbourne’s Docklands Stadium, young winger Robbie Kruse set up veterans Mark Bresciano and Tim Cahill, and then grabbed a goal of his own, before skipper Lucas Neill rounded off the scoring with his first international goal.
Australia coach Holger Osieck said he felt “pretty sure” Australia now had the momentum to beat Iraq and get to Brazil. Jordan and Australia had been locked on seven points each before Tuesday’s game.
After a cagey opening in Seoul, Anzur Ismailov’s long shot forced a save from South Korea’s Jung Sung-ryong, and Lee Keun-ho was guilty of a terrible miss when he sliced an easy shot wide from close range.
Uzbekistan’s Ulugbek Bakaev drew South Korea goalkeeper Jung into action again with a shot, but he also passed up a golden chance when he met Server Djeparov’s cross unmarked at the far post, but planted his header high and wide.
After 41 minutes, imposing South Korea striker Kim Shin-wook’s knock-down fell to Lee Myoung-ju, but Uzbek custodian Ignatiy Nesterov dived low at his feet to deny the debutant midfielder.
However, the Korean pressure told just a minute later when Kim Young-gwon’s arcing cross from deep on the right fell to the unfortunate Akmal Shorakhmedov, who could only direct it into his own net.
After the break, Timur Kapadze fired over in a strong spell for the visitors, but South Korea gradually regained control and had the best chances of the second half.
“I felt this match would come down to a single goal,” South Korea coach Choi Kang-hee said. “We were able to win because our players never lost their concentration.”
Jordan had described the game against Australia as the biggest in their history, but they were disappointing in Melbourne and never recovered after falling behind on 15 minutes.