The big day is finally here!
England take on Wales on Tuesday for a place in the last 16 of the World Cup. Gareth Southgate's side will progress if they avoid a 4-0 defeat to their neighbours.
Rob Page's team face a more daunting task to keep their hopes alive. If they beat England - by any score-line - and Iran's game against the USA ends in a draw, they will go through. If Iran or the United States win, Wales will need beat England by four goals.
The US need to beat Iran to leapfrog them and snatch the final spot. In Group A, the Netherlands have reached the last-16 thanks to a 2-0 win over Qatar, who have made history as the first host nation to exit the tournament losing all of their group games. Meanwhile, Senegal got the better of Ecuador, winning 2-1 to clinch second spot in Group A.
Follow all the action as it happens below...
20:33Felix Keith
Iran pushing
Iran have been much, much improved since the second half kicked off. They're getting the long throw-ins out and Saman Ghoddos' introduction has made a difference.
20:27Felix Keith
Why Iran sang the national anthem
Iran's players sang the national anthem ahead of their crucial World Cup match against the USA following reports of political pressure in their home country.
Read the full story here.
20:16Felix Keith
Iran chance
Second-half substitute Saman Ghoddos almost makes an immediate impact, but his header is over the USA crossbar.
Better from Iran, though.
20:07Felix Keith
Kick off
We're back underway.
USA will be hoping for more of the same. Iran have to turn the tide if they are to stay in the competition.
19:53KEY EVENT
Half-time: USA 1-0 Iran
Christian Pulisic has netted the only goal. The USA have been by far the better team and deservedly lead.
Iran will have to improve in the second half.
19:53Felix Keith
Goal ruled out!
Timothy Weah runs in behind and stabs in a lovely finish, but the offside flag is up. Iran are saved on the stroke of half-time.
19:47Felix Keith
USA mess up three-on-two
Josh Sergant and Timothy Weah conspire to mess up a great chance on the counter-attack for USA, who are completely dominating this game.
19:40KEY EVENT
GOAL! USA 1-0 Iran
Christian Pulisic comes up trumps for USA when it really matters.
Sergino Dest heads it across the six-yard box where Pulisic side-foots it in.
19:39Felix Keith
USA on top
USA are by far the better team in this one. Iran are yet to fire a single shot in on their opponents' goal, while the Americans have attempted seven shots.
19:30Felix Keith
Chance!
Josh Sargent's shot is deflected up into the air, but Timothy Weah can only nod it into the Iran goalkeeper's gloves. Wasted opportunity for USA.
19:27Felix Keith
Pulisic is USA's biggest hope
19:23Felix Keith
Iran nearly in on goal
Sardar Azmoun is free in the six-yard box, but the pass is cut out by the USA defence.
19:15Felix Keith
USA supporter ejected
A supporter has been ejected from the Al Thumama Stadium ahead of USA's final World Cup group clash against Iran for wearing a rainbow armband.
Read the full story here.
19:09Felix Keith
Lively start
Chrisian Pulisic almost raced right down the middle of the pitch, but he was stopped on the edge of the area.
Iran have since had a nice period of pressure.
19:02Felix Keith
Kick off
Iran kick us off and we're away at the other game in Group B.
18:52Felix Keith
Follow Wales v England
Reminder: we have a dedicated blog for tonight's big match.
Here we will be keeping an eye on both games and providing the wider picture.
18:39Felix Keith
USA aiming to build on draws
The United States are unbeaten in Group B, following draws with Wales and England.
They will be aiming to go one better against Iran tonight.
18:28Felix Keith
Reminder of the Group B situation
England are top of the pile, with four points from their two games.
Iran sit second on three points, with the USA third on two and Wales bottom with one.
All four teams can still qualify for the last-16.
18:10KEY EVENT
Iran team news
Iran XI vs USA: Beiranvand, Majid Hosseini, Pouraliganji, Rezaeian, Mohammedi, Nourollahi, Ezatolahi, Gholizadeh, Haji Safi, Taremi, Azmoun.
18:09KEY EVENT
USA team news
USA team vs Iran: Turner; Dest, Ream, Carter-Vickers, Robinson; Adams, Mensah, McKennie, Pulisic, Weah, Sargent.
18:04Felix Keith
Iran vs USA (7pm)
17:45Felix Keith
Wales team news
Wales XI vs England: Ward; N Williams, Mepham, Rodon, B Davies; Allen, Ampadu; Bale, Ramsey, James; Moore.
You can follow that game on our dedicated live blog here. On this page we will be taking a broader focus, with Iran vs the USA included.
17:43KEY EVENT
England line-up vs Wales
England XI v Wales: Pickford, Walker, Stones, Maguire, Shaw, Rice, Henderson, Bellingham, Foden, Rashford, Kane (c)
17:38Felix Keith
Stage set for England v Wales
17:22Felix Keith
Touching tribute from Senegal
17:13Felix Keith
Contrasting emotions in Group A
17:05Felix Keith
Qatar make unwanted history
Qatar's World Cup is over - and they've made history.
They are now officially the worst hosts of all time, after losing all three of their matches, against Senegal, Ecuador and the Netherlands.
They did score a goal, but it has not been the tournament they would've hoped for.
16:59KEY EVENT
Full-time: Ecuador 1-2 Senegal
Senegal have done it! They go through second in Group A thanks to a narrow and nervy win over Ecuador.
Ismaila Sarr's penalty and Kalidou Koulibaly's volley are enough, with Moises Caicedo's goal counting for nothing.
Ecuador's players are visibly distraught, strewn all over the turf, as Senegal celebrate in front of them.
16:57KEY EVENT
Full-time: Netherlands 2-0 Qatar
Netherlands are safely through to the last-16 thanks to a comfortable win over the hosts, who exit without picking up a point.
Goals from Cody Gakpo and Frenkie de Jong have sent the Dutch through top.
16:48Felix Keith
Timing running out for Ecuador
We're in the final few minutes of normal time and Ecuador are running out of gas. They need a goal, otherwise they will be out of the World Cup.