England's unlikely batting saviour Jack Leach insists all the pressure is on Ireland as they look to complete what would go down as one of the biggest shocks in Test history.

The inaugural Specsavers Test between the neighbouring nations looks certain to come to a conclusion at Lord's on Friday, with the hosts resuming 181 ahead with a solitary second innings wicket in hand.

That all three results are still possible owes much to Leach, who turned a bit-part role as nightwatchman on the first evening into a star turn on day two.

The lifelong tailender defied a first-class average of less than 11 to strike a career-best 92, the best batting performance of a low-scoring match and the centre-piece of his side's 303 for nine.

But while defeat would deal a huge blow to England, humbling them in stark fashion ahead of next week's Ashes, Leach believes the opportunity in front of the Irish in just their third Test appearance changes the dynamic.

"I actually think there is pressure on Ireland. It's the first time they've had this experience of probably being favourites to win a game," he said.

"We don't need to hide away from that. This is a huge day for the whole team. But we've also talked in the dressing room about the game at Edgbaston last year against India where they were chasing 194 and came 31 short.

"The boys believe this is a tougher wicket than that one so we'll have big belief going in. We'll have to bowl really well but I think we've got a great chance."

English prospects would have been much bleaker without Leach's steadfast resistance, a knock which put his previous career best of 66 for Somerset in the shade and even shunted Jason Roy's 72 on debut into the shade as the pair put on 145 for the second wicket.

The 28-year-old went on to reveal that his father, Simon, had passed up the chance to watch his big moment live after hearing predictions of record temperatures in the capital.

"He was going to come but he saw the weather forecast and said it was too hot," Leach said with a smile.

"I don't think it would have been a good place for him to be, he could have died! I think it was best he stayed at home in the cool.

"I gave him my house key and he went over so he's literally been at mine watching the whole time. I'll catch up with him later on."

Ireland's man of the day was Mark Adair, the 23-year-old debutant from Holywood who pegged back the resistance by removing England captain Joe Root, Jonny Bairstow and Chris Woakes in a brilliant spell.

His reaction to the prospect of recording a famous win that would go down as one of the great shocks was almost comically low key.

"It'd be good, like. Fairly nice," was his estimation.

"There's still a result to come out of this game. It probably won't be no result. But we still have to take another wicket first. We have to focus on what we need to do."