English Prem leaders Northampton snatched a 21-17 win against Saracens thanks to Archie McParland's late try at the Tottenham Hotspur Stadium on Saturday.
McParland touched down in the closing stages to cap a dramatic clash in north London.
Fergus Burke had put sixth-placed Saracens in the driving seat with a 73rd-minute penalty after his team battled back from a 14-0 deficit.
McParland and Tom Litchfield crossed over for Northampton in the first half, with Fin Smith converting both scores.
Smith was forced off due to a head injury and Saracens hit back through tries from Tobias Elliott and Theo Dan.
But George Furbank combined with Litchfield to set up McParland's second try with just two minutes remaining.
Northampton are now six points clear at the top of the table.
Bristol's play-off hopes were dealt a major blow in a 18-14 defeat against struggling Harlequins at the Principality Stadium.
Harlequins ended a run of six successive Prem losses stretching back five months thanks to tries from Alex Dombrandt and Rodrigo Isgro.
Jarrod Evans kicked a penalty and Jamie Benson converted Isgro's score before landing a 79th-minute penalty.
Fitz Harding and Steven Luatua scored Bristol's tries and James Williams converted both, but they still slipped seven points behind fourth-placed Exeter with six games left.
Jamie Blamire scored two tries as Leicester routed Gloucester 36-17 at Villa Park.
Will Wand, Gabriel Hamer-Webb, Orlando Bailey and Harry Wells were Leicester's try scorers, with Billy Searle adding two conversions and James O'Connor one.
Matias Alemanno, Will Joseph and Dian Bleuler scored Gloucester's tries, one of which Charlie Atkinson converted.
The win kept Leicester in third place, with Gloucester stuck on just two wins from 12 league matches.