A last-minute penalty from halfway by Elliot Daly gave Wasps a 26-24 victory over Gloucester and a vital four points in their battle against relegation from the Premiership.
Daly was called upon to take the crunch kick after former Gloucester player Nicky Robinson had missed with four penalties - and the nerveless centre hammered over the matchwinner at Adams Park.
With three games remaining, Wasps now have an eight-point lead over bottom club Newcastle, with the sides due to meet in the last match of the season at Adams Park.
Sunday's game was a tight affair which came to life in the second half.
Wasps, inspired by Nic Berry and Billy Vunipola, were the better team in the first half and at one stage led 23-10.
However, Luke Narraway and Johnny May underpinned an impressive Gloucester rally which saw them lead until Daly's late effort.
George Lowe scored one try and saved two others as Harlequins produced an heroic defensive performance to beat Saracens 24-19 in front of a world record crowd and extend their lead at the top of the Aviva Premiership.
Lowe is on Stuart Lancaster's list of potential England stars of the 2015 Rugby World Cup and the 22-year-old Harlequins centre proved why on the biggest stage club rugby has ever seen, with a crowd at Wembley of 83,761.
After Jordan Turner-Hall's try had put Harlequins ahead, Lowe produced a top class finish to score his side's second of the afternoon and Danny Care added their third after the break.
Saracens then threw the kitchen sink at Harlequins but Lowe kept the Premiership champions out with brilliant try-saving tackles on Michael Tagicakibau and Chris Wyles in the space of three minutes.
Harlequins were under siege and had three men sin-binned - Joe Marler, Care and Nick Easter - as they weathered wave after wave of Saracens attacks.
Richard Wigglesworth finally stole over when Marler and Care were both off the field and Owen Farrell added the conversion to his four first-half penalties.
That was enough to secure Saracens the losing bonus point and move them back up to second place - but Harlequins held out for the victory to open a six-point lead at the top.
Bath's hopes of snatching a Heineken Cup spot next season are fading fast after Northampton shrugged off the midweek suspensions of skipper Dylan Hartley and Calum Clark to claim a comfortable 26-6 win at the Recreation Ground.
Saints duly moved back into the play-off places thanks to a first-half penalty try converted by Ryan Lamb, who added two penalties and a drop goal before the break.
Stephen Myler converted a catch-and-drive try credited to former Bath hooker Andy Long to seal the victory.
Stephen Donald kicked two penalties for the home side, whose season is petering out with owner Bruce Craig already seeking a new man to take charge of the playing side from Sir Ian McGeechan.
Exeter Chiefs continued to push hard for a semi-final spot as they secured an 18-11 victory over London Irish.
The Devon side outscored the Exiles two tries to one with all the visitors points coming from full-back Tom Homer as the visitors slipped to their sixth league defeat in a row.
Gonzalo Camacho and James Hanks were the men to cross for the Chiefs.
On Friday night, Jimmy Gopperth grabbed a relegation lifeline for Newcastle with a nerve-tingling 76th-minute penalty at Kingston Park.
Gopperth's strike saw the Falcons battle back from 19-12 down to beat Sale 22-19 and cut the gap at the bottom between themselves and Wasps to just four points.
With Dean Richards, who takes over from Gary Gold as Newcastle director of rugby next season, in the stands, the Falcons stretched their unbeaten home run to five games with a huge second half performance.
Tim Swinson scored Newcastle's only try of the match with the other 17 points for the hosts coming from the boot of Gopperth.
Tries from Rob Miller, Johnny Leota and James Gaskell weren't enough for Sale.
In Friday night's other game, former England fly-half Andy Goode was sent off as Worcester lost 43-13 against Leicester at Welford Road.
Goode, who had already been sin-binned, received a straight red card in the 35th minute from referee Wayne Barnes for a flying shoulder charge on England flanker Tom Croft and was booed by the fans of his former club as he walked off the pitch with his head bowed.
Leicester, who were leading 10-3 at the time, took full advantage of the extra man and won with tries from Scott Hamilton, George Chuter, Croft, Martin Castrogiovanni, Thomas Waldrom, Tom Youngs and George Ford.
Toby Flood kicked three conversions, and Ford one, while Ceri Jones scored a try for Worcester, converted by replacement Danny Gray. He and Goode also slotted penalties.