How Senegal managed to emphatically beat Iraq to qualify for the knockout rounds

Here were the three key reasons for Senegal's  emphatic victory against Iraq:

Playing with 10 men haunts Iraq

Let us start with the obvious thing: Rebin Sulaka's red card 13 minutes in, something head coach Graham Arnold described as "a stupid red card," did the most damage for Iraq. The defender brought down his marker, denying what would have been a clear goalscoring opportunity.

While the Lions of Mesopotamia did a good job of keeping their opponents out in the first half, the fatigue started to show, and within the space of three second-half minutes, the score was 3-0.

Iraq boss Graham Arnold described the second goal as "a blow for the players mentally.

"It was obviously tough getting a red card so early in the game," the Australian said. "We were playing against Senegal, who are 12th or 13th in the world. When you make those types of mistakes, you get punished."

It was evident that Iraq were always going to be up against it, and despite their numerical disadvantage, they did manage to create a couple of half-chances in the opening half. That deserves credit, even if they still had something to play for at the time.

Arnold also highlighted the lack of quality in Iraq's domestic league, which was not a help for his side.

"Your national team is as strong as your local league," said the 62-year-old. "If your local league is not that strong, you will get punished against these types of opponents. They have only ever seen these types of opponents on TV - they have never played against players like these before."

Still, even with the quality aside, playing down a man for the overwhelming majority of the match is not helpful, something the Iraqis learned the hard way.

Senegal wake up in second half

Senegal's first-half showing was not enough to get them the goals they needed. With just two shots on target from 10 in total, the Lions de la Teranga failed to create serious goalscoring chances to test the Iraqi keeper.

The contrast between the first and second halves were large. Just before the Senegalese coach Pape Thiaw made a triple change, a second goal was scored. Minutes later, a third, with a fourth coming shortly after the hydration break.

At that point, Senegal were showing the potential needed to get the three points and keep themselves alive. If that was also shown in the opening 45, the scoreline would have been far more damaging for their opponents.

"Since the last 3-4 preparation games as well as the start of the competition, we had not led," stated Thiaw. "So I think that played an effect, was on the mind of the players.

"After half time, once we remobilised and asked to keep the ball and control the game 11 versus 10, we were able to make changes. They were able to bring something to the game as well."

Strength of bench shown

Any team that wants to go far in the World Cup will need to have a deep bench. France are probably the deepest team among the 48, but several other nations can speak of having a very strong 26-man squad.

Senegal showed just how their team is, given the players they were able to bring off the bench. Just after their second goal, Thiaw made a triple change. Two of those three players, Pape Gueye and Iliman Ndiaye, got on the scoresheet.

Yes, circumstances are worth keeping in mind. Senegal were up a man, and that has to be factored in. However, that should not take away from just how good the duo were.

With the Lions de la Teranga now safely through to the knockout stages, being able to count on the players not in the starting 11 could decide just how far they go.

View the match stats on Flashscore.