Jimmy Gopperth kicked Wasps into the European Champions Cup semi-finals with a last-gasp conversion in a thrilling 25-24 victory over Exeter Chiefs.
Wasps trailed 14-6 at half-time after Thomas Waldrom went over twice for the visitors, but Charles Piutau touched down early in the second period to reduce the deficit.
A Harry Williams try and five points from the boot of Gareth Steenson saw Exeter open up a 24-11 advantage just short of the hour mark, but Wasps came roaring back.
Frank Halai's score kept the hosts' hopes alive and, with Exeter — chasing its first semi-final appearance — looking set to cling on for a place in the last four, Piutau set up a dramatic finish, leaving Gopperth facing a kick from the right wing to complete the turnaround.
Gopperth coolly split the posts, throwing his arms in the air before being congratulated by his team-mates, with Wasps now set for a semi-final against Saracens, which beat Northampton Saints 29-20.
Saracens was not at its best but overcame an injury-hit Northampton.
Mark McCall's men trailed 10-6 at the break before powering into a 29-13 lead in the second term courtesy of 13 points from the boot of Owen Farrell and tries from Chris Ashton and Chris Wyles.
Courtney Lawes touched down late on, but it was not enough for Northampton, as Saracens reached the last four of Europe's premier club competition for the fourth consecutive season.