Heimir Hallgrimsson has warned the Republic of Ireland they will need to be better than they were in Nations League victory over Finland if they want to qualify for the 2026 World Cup finals.

Evan Ferguson’s header secured a 1-0 win over the Finns, who they beat 2-1 in Helsinki last month, to send Ireland into Sunday’s final League B2 fixture against England – 3-0 winners in Greece – at Wembley on a high.

However, they needed Caoimhin Kelleher’s second-half penalty save to preserve their clean sheet, while Finland also hit the woodwork.

Hallgrimsson said: “We are not jumping for joy today, I think we could have done much better than we did. Obviously it was enough to win and that is a good thing.

“But we know we need to work a lot as a unit, as a group to progress because if we want to qualify for the World Cup, we need to beat teams that are higher-ranked than us and get points from them, and I would say with this performance, we probably wouldn’t.

“But it was enough today and that’s good, and we’ll build on that. It’s good to have a win for the spirit and I think these players need to experience that as often as they can.

“But we’re under no illusion we need to improve.”

If Ferguson’s goal – a close-range header from Mikey Johnston’s inch-perfect cross – proved decisive, it would not have had Kelleher not dived to his right to keep out substitute Joel Pohjanpalo’s second-half penalty, awarded for handball against Ferguson after a VAR review.

That provided the Liverpool keeper with sweet redemption after his error in Athens last month handed Greece a second goal to kill off Ireland’s chances of snatching a draw.

Hallgrimsson said: “He really answered for that today. His all-round performance was really good and I’m so happy, really happy with him.

“Caoimhin, of course, is playing really well at this stage in is career. He’s not conceding goals at his club and I hope he’s going to bring that to Ireland as well.”

Hallgrimsson and his players will head for London with six points from their five fixtures to date and knowing they will finish third in the table regardless of what happens at Wembley, where England need to match Greece’s result in Finland to ensure their return to League A.

Asked if the game represented a free hit, the Icelander said: “I think even though it’s maybe not fully deserve to go with a clean sheet, it gives us a certain confidence going into the England game.”

Opposite number Markku Kanerva was left to reflect on what might have been as events in Dublin conspired against his team.

He said: “Of course we are not satisfied with the result. We played OK, but that’s not enough, We didn’t score. We had good chances, missed a penalty, a couple of shots against the post and it’s small margins which decides it today.”