Tom Brown scored a late try to seal a dramatic 36-35 victory for Edinburgh over Harlequins as the Scottish side took control of European Challenge Cup Pool 5.
The hosts led 31-14 at half-time at Murrayfield with Alan Dell, Blair Kinghorn, Nasi Manu, Hamish Watson and Damien Hoyland all finding the line.
But the visitors roared back after the break, with Kyle Sinckler and Mat Luamanu adding to a penalty try to make it 35-31 after 67 minutes despite losing both Charlie Walker and Joe Marler to yellow cards.
The last word went to Brown, however, as the wing just managed to ground the ball over the line with six minutes left, sending Edinburgh three points clear of Quins.
There was a similarly tight tussle at Sixways where Worcester were pipped 25-24 by Brive in their Pool 3 clash.
Centre Ben Te'o bagged one of the home side's two tries, but Takudzwa Ngwenya, skipper Said Hireche and Thomas Acquier all replied in kind for the visitors as they ended a run of eight consecutive Challenge Cup defeats on the road.
The other Pool 3 clash saw Enisei-STM take another step towards a maiden appearance in the knock-out phase with a 38-18 win over Newport Gwent Dragons.
The Russian side beat Worcester last time out and two tries apiece from centre Dmitrii Gerasimov and hooker Stanislav Selskii proved enough to take them to the top of the group at the expense of the Dragons.
Gloucester, meanwhile, built on last weekend's impressive away win in Bayonne by making short work of Pool 1 rivals Benetton Treviso with a 37-8 bonus-point win at Kingsholm.
The Ospreys continue to lead the way in Pool 2 after they snapped a run of 10 away defeats at the hands of Top 14 sides by downing Lyon 31-13 at the Matmut Stadium.
Highly-rated 19-year-old wing Keelan Giles scored a hat-trick as the Welsh side chalked up back-to-back bonus-point victories.