Leinster survived a late scare from Bath at the Aviva Stadium today to book a place in the Champions Cup semi-finals.

Ian Madigan kicked all of the Irish province's points with a perfect six from six penalties to give the three-time European champions a last-four tie away to the winner of tomorrow's encounter between reigning titleholders Toulon and Wasps.

Yet they got there by the skin of their teeth as Bath outscored them by two tries to nil, coming from 15-5 down at half-time to make a real fight of an at-times scrappy contest.

Leinster were the better of the sides in a scrappy opening period which highlighted the rustiness of the collectives following eight weeks of Six Nations rugby.

Matt O'Connor's side missed 14 tackles in 40 minutes, at least a third of those in the concession of Bath's try on 20 minutes, Ian Madigan failing to find touch with his kick out of hand leading to Ford's score.

Horacio Agulla collected the errant kick, raced past a stretching Cian Healy, Francois Louw continuing the attack and evading a Madigan tackle attempt before George Ford beat another tackle, sold a dummy and scored all too easily for Leinster's liking.

Yet it was the only try of the half, Ford missing his conversion having already sent a penalty wide.

Madigan, though, atoned for his errors with five penalties from five attempts as Bath paid the price for poor discipline.

The English side compounded sloppy errors by conceding eight first-half penalties and also lost full-back Anthony Watson to a yellow card in the 25th minute after he took out an airborne Rob Kearney as the Leinster back fielded a high ball.

Three of those five penalties came in Watson's absence, leaving the Premiership trailing the Irish province 15-5 at half-time.

The home side were forced into a substitution a minute into the second half when Fergus McFadden's head made contact with Kyle Eastmond's shoulder, prompting the introduction of Zane Kirchner.

McFadden looked to have been knocked unconscious by the collision but after treatment on the pitch was able to walk to the dressing rooms. His replacement almost made an immediate impact, Kirchner nearly finishing a fine backs move in the corner, only to be tackled into touch by Ford.

And it was the Bath fly-half who made the difference at the other end, moments later, making a break following an attacking lineout before offloading to lock and captain Stuart Hooper to score next to the posts. Ford converted the try from close range and it was game on at 15-12.

A scrum penalty for Leinster allowed Madigan to stretch the lead to six points but as the game began to open up it was Bath who looked the more comfortable while the home side continued to drop off tackles.

Their reward did not come until the 71st minute when Ford kicked a penalty to set-up a nervous finish for the Leinster fans and some poor box kicking from substitute scrum-half Eoin Reddan kept them on edge to the end, allowing Bath to keep the pressure on and Leinster in their own 22.

The siege was not lifted until the clock had ticked past 80 minutes, as Leinster defended for their European lives, relieved only when substitute Bath lock Matt Garvey was penalised for coming in at the side of a ruck. It wasn't pretty but Leinster had found their way through to the semi-finals.

LEINSTER: R Kearney (G D'Arcy, 71); F McFadden (Z Kirchner, 41), B Te'o, I Madigan, L Fitzgerald; J Gopperth, I Boss (E Reddan, 57); C Healy (J McGrath, 59), S Cronin (R Strauss, 66), M Ross (M Moore, 50); D Toner, M McCarthy (T Denton, 71); J Murphy, S O'Brien, J Heaslip – captain.

Replacement not used: D Ryan

BATH: A Watson; H Agulla (T Homer, 66), J Joseph, K Eastmond (S Burgess, 60), M Banahan; G Ford, M Young (P Stringer, 65); P James (N Auterac, 52), R Webber (R Batty, 50), K Palma Newport (M Lahiff, 57); S Hooper - captain, D Attwood (M Garvey, 62); C Fearns (A Fa'osiliva, 57), F Louw, L Houston.

Referee: Jerome Garces (France)