(Reuters) - With the World Cup knockout phase having begun, here is an overview of the teams advancing to the last 16 at the tournament in Qatar:

HOW DOES THE KNOCKOUT STAGE AT WORLD CUP 2022 WORK?

* In the knockout stage the teams will play each other once, with the winning team going to the next round. There are total of four rounds: Round of 16, quarter-finals, semi-finals and final, which will take place on Dec. 18.

* There is also a third place playoff between the losers of the semi-finals.

* If the scores are equal at the end of normal playing time, extra time is played for two periods of 15 minutes each. If the score is still tied, this is followed by a penalty shoot-out to determine the winners.

WHICH TEAMS HAVE QUALIFIED FOR THE KNOCKOUT STAGE?

GROUP A

* The Netherlands secured a place in the last 16 with victories over African champions Senegal and hosts Qatar, topping Group A despite a 1-1 draw with Ecuador.

* The reigning African Champions started the World Cup with a loss to the Netherlands, but they turned their fortunes with a 3-1 win over hosts Qatar and a decisive 2-1 win over Ecuador.

GROUP B

* England punched their ticket to the knockout phase as top of Group B with 7 points, following emphatic victories against Wales and Iran and a goalless draw with the United States.

* The United States qualified as runners up of Group B after a 1-0 victory over Iran in a match overshadowed by political tension following draws with Wales and England.

GROUP C

* Argentina clawed back the top spot in Group C with wins over Mexico and Poland after a shocking loss in the opener against Saudi Arabia. They will next face Australia on Saturday.

* Poland clinched a spot in the last 16 as runners-up of Group C after a win over Saudi Arabia, a draw with Mexico and a loss to Argentina. They meet France on Sunday.

GROUP D

* Reigning champions France delivered on expectations and became the first team to qualify for the last 16 with consecutive Group D wins over Australia and Denmark, followed by a 1-0 loss to Tunisia.

* Australia claimed a spot in the last 16 as Group D runners-up with 6 points from wins over Tunisia and Denmark. They go on to face Argentina on Saturday.

GROUP E

* Japan surged into the last 16 as the unlikely winners of Group E after the Samurai Blue staged two stunning comeback wins over Germany and Spain, losing only to Costa Rica. They will face Croatia on Monday.

* Spain clinched a spot in the last 16 with a blowout against Costa Rica, followed by a draw with Germany and a loss to Japan. They will meet Morocco on Tuesday.

GROUP F

* Morocco topped Group F with wins over Canada and Belgium following a goalless draw with Croatia, and will play against Spain on Tuesday.

* Croatia joined the last 16 after two goalless draws with Morocco and Belgium and a 4-1 victory over Canada. They will next face Japan on Monday.

Group G:

* Brazil booked their ticket for the knockout stage with back-to-back wins against Switzerland and Serbia, followed by a 1-0 loss to Cameroon. They will face South Korea on Monday.

* Switzerland secured the runners-up spot in Group G with a 3-2 win over Serbia and a victory over Cameroon, and will go on to play Portugal on Tuesday.

GROUP H

* Portugal finished Group H with a defeat by South Korea but held on to their top spot to face Switzerland on Tuesday.

* South Korea clinched entry to the knockout stage with a last-gasp win over already-qualified Portugal, following a goalless draw with Uruguay and a loss to Ghana.

WHAT IS THE SCHEDULE FOR THE KNOCKOUT STAGE?

DATE FIXTURE TIME VENUE

Dec. 3 Netherlands v 1500 Khalifa

United States International

Stadium

Dec. 3 Argentina v 1900 Ahmad bin Ali

Australia Stadium

Dec. 4 France v Poland 1500 Al Thumama

Stadium

Dec. 4 England v 1900 Al Bayt

Senegal Stadium

Dec. 5 Japan v Croatia 1500 Al Janoub

Stadium

Dec. 5 Brazil v South 1900 Stadium 974

Korea

Dec. 6 Morocco v Spain 1500 Education

City Stadium

Dec. 6 Portugal v 1900 Lusail Iconic

Switzerland Stadium

Dec. 9 Quarter-final 1 1900 Lusail Iconic

Stadium

Dec. 9 Quarter-final 2 1500 Education

City Stadium

Dec. 10 Quarter-final 3 1900 Al Bayt

Stadium

Dec. 10 Quarter-final 4 1500 Al Thumama

Stadium

Dec. 13 Semi-final 1 1900 Lusail Iconic

Stadium

Dec. 14 Semi-final 2 1900 Al Bayt

Stadium

Dec. 17 Third place 1500 Khalifa

playoff International

Stadium

Dec. 18 Final 1500 Lusail Iconic

Stadium

WHICH TEAMS ARE OUT OF THE WORLD CUP?

* Group A: Ecuador and Qatar

* Group B: Iran and Wales

* Group C: Mexico and Saudi Arabia

* Group D: Tunisia and Denmark

* Group E: Germany and Costa Rica

* Group F: Belgium and Canada

* Group G: Cameroon and Serbia

* Group H: Uruguay and Ghana

(Compiled by Tommy Lund in Gdansk; Editing by Shri Navaratnam)