A cunning 120th minute substitution proved planning is key when it comes to winning cup ties.

A record attendance of nearly 1,200 fans in Felixstowe saw an epic finale as Ipswich Town Women marched past the Saints to secure a last eight place in the WFA Cup.

It took extra time and penalties to settle this fifth round match at Felixstowe's Goldstar Ground in front of 1,176 fans.

After a fairly uneventful 90 minutes, the Blues were blasted in front by substitute Anna Grey midway through the second part of extra time but suffered a heartbreak last gasp equaliser by Southampton keeper Kayla Randall who went up for a corner and met the flag kick perfectly with her header.

But the Tractor Girls were not to be denied and their penalties preparations paid off and an inspired substitution to put on Lucy O'Brien set them on their way to a 4-2 shoot out success.

Despite not playing even a second of the 120 minutes due to fractured wrist, O'Brien was highly instrumental in the Tractor Girls clinching victory in the penalty shoot out.

The Cambridgeshire student fractured her wrist in Town's previous FA Cup win, 1-0 over Newcastle, and while she would was ruled out to play on the field, her penalty prowess was predicted and planned for.

None of the other Town takers missed either, with Issy Bryant, Zoe Barrett and Paige Peake all scoring with powerful and precise kicks, while Blues keeper Sarah Quantrill made two excellent saves to secure victory.

"I knew all week I would not be able to play because of my wrist but I also knew that if it did go to penalties I could be involved," O'Brien told Nub News. "I take penalties regularly and I backed myself to score.

"I didn't think I would be needed when Anna scored but then they equalised right at the end so I had to quickly get myself ready and fortunately was able to put it into the back of the net."

O'Brien has been taking penalties since she was a youth player with MK Dons, and Town's U21s and put the secret down to confidence and practice

The 18-year-old added: "It is something I have done since I was much younger and I'm used to it although it doesn't get any easier, especially under pressure taking one in front of 1,100 people. It was a big moment.

"I like going first because it gets it out of the way and it helps give the other girls confidence."

The Cambridgeshire sixth former travels to Suffolk to train and play and added: The fans here in Felixstowe make all that worthwhile. They were with us every step of the way and helped get us get over the line."

Manager Joe Sheehan hailed Lucy and fellow teenager Issy Bryant who told the second penalty.

"What an utterly incredible game, it had everything in the end," said Sheehan.

"We had planned for penalties, we knew which way their players would be going so even when their keeper scored with that final header, we were confident we could win.

"Our first two penalty takers are very young and showed incredible courage.

"We knew Lucy could not play with her wrist but we always planned to put her on for penalties."

The Town boss also praised the Blues support in Felixstowe and said: "Nearly 1,200 is a great crowd and I hope that inspired a few to come back and watch us again.

Skipper Bonnie was delighted the four takers were on target and joked she was relieved as she had been the fifth penalty taker if needed.

She said: "All the penalties were really well struck and Sarah knew which way to go for all hers.

"Both teams fought hard but in the end we just had enough composure to get through."

Town's goal in normal time was a moment of quality with a neat piece of play at a throw in saw Eva Hubbard send in adept cross which Saints failed to clear and Horwood nodded back into the box for Grey to volley in.

Ipswich also had the ball in the back of the net when Eloise King powerfully shot past the keeper, but she was ruled offside.

The Tractor Girls will find out on Tuesday evening who they will meet in the quarter finals, with Coventry United a popular choice of who they want to play.