The hosts made a return to winning ways in qualifying on Tuesday, while their visitors fell just short against Brazil, and will look to bounce back.
Match preview
After narrowly losing their opening World Cup Qualifying game 1-0 to Argentina in 2020, Ecuador bounced back in style, picking up three straight wins as they began with an eye-catching 4-2 victory over Uruguay before defeating Bolivia 3-2 and thrashing Colombia 6-1.
When they returned to action this year, Gustavo Alfaro's side fell to defeats at the hands of Brazil and Peru, before they had a somewhat underwhelming Copa America campaign in the summer.
Despite not picking up a win, La Tricolor scraped through the group stage with three points, including an impressive draw with Brazil, and they met Argentina in the quarter-finals, with Rodrigo De Paul, Lautaro Martinez and Lionel Messi getting on the scoresheet as the eventual winners dumped Ecuador out.
In their first game since that exit, Alfaro's men bounced back to winning ways in qualification on Thursday, as they beat Paraguay 2-0.
The game looked set to end goalless, until Felix Torres finally put La Tricolor ahead in the 88th minute, and Michael Estrada added a second deep into injury time to secure the three points.
As a result, they have managed to keep hold of third spot in the World Cup Qualifying group, and will be keen to continue their impressive showing to reach next year's tournament after failing to qualify for the 2018 World Cup in Russia.
They take on a Chile side who will hope to quickly climb the table after a disappointing record so far, having started the campaign with a defeat to Uruguay and a draw with Colombia.
Martin Lasarte's men then beat Peru 2-0 to secure their first three-point haul, but would lose to Venezuela and draw with Argentina and Bolivia to head into the Copa America with six points from six World Cup Qualifying games.
La Roja began the continental campaign in style, drawing with Uruguay and Argentina and defeating Bolivia to book their spot in the knockout stage, but a defeat to Paraguay saw them fall to a fourth-placed finish and meet pre-tournament favourites Brazil in the quarter-final.
Chile battled hard but were eventually knocked out after a 1-0 defeat, and they returned to action for the first time on Friday, again meeting the Selecao.
In a repeat of the Copa America quarter-final, Brazil picked up a narrow 1-0 win over Lasarte's men thanks to Everton Ribeiro's 64th-minute winner, meaning La Roja now sit seventh in the South American qualifying group.
With their task looking tougher than ever, Chile will be desperate to put a win on the board to boost their chances of reaching next year's World Cup, having also missed out in 2018.
Ecuador World Cup Qualifying - South America form:
Ecuador form (all competitions):
Chile World Cup Qualifying - South America form:
Chile form (all competitions):
Team News
Ecuador will be led by forward Enner Valencia, who needs one goal to surpass Agustin Delgado as the nation's all-time top scorer with 32 goals.
Michael Estrada will push to join the captain in the attacking line, having come off the bench to find the net last time out.
Experienced winger Angel Mena should complete the front three, while first-choice midfielders Jhegson Mendez and Moises Caicedo were both absent last time out and could again be missing on Sunday.
Chile remain without star forward Alexis Sanchez, who missed the Copa America through injury.
In his absence, Eduardo Vargas has led the line well, surpassing 100 caps and reaching 40 international goals.
Ben Brereton Diaz also recently declared for Chile, and he netted his first goal at the summer's tournament, but the Blackburn Rovers man has not been able to join the squad, with the English system refusing to release players for international games in COVID-19 red-listed countries.
Further back, they still boast plenty of experience with the likes of centre-back Gary Medel and midfielder Arturo Vidal, although Erick Pulgar and crucial defender Guillermo Maripan will miss out through suspension.
Ecuador possible starting lineup:
Galindez; Leon, Arreaga, Torres; Castillo, Gruezo, Gaibor, Estupinan; Mena, Valencia, Estrada
Chile possible starting lineup:
Bravo; Isla, Diaz, Medel, Mena; Vidal, Aranguiz, Jimenez; Morales, Vargas, Palacios
We say: Ecuador 1-1 Chile
While Ecuador have demonstrated far superior form in the World Cup Qualifying group so far, but Chile's predicament looks dangerous and they will be desperate not to fall to another defeat.
Even without several key players, La Roja arguably have more quality in their squad than their opponents, and we back them to come away with a result, albeit not all three points.