Exeter Chiefs produced a ferocious second-half comeback to defeat Newport Gwent Dragons 23-19 and surge back to the top of Pool Four.
Rob Baxter's men trailed 16-6 at the interval following a stunning try from Toby Faletau. But with super-sub Gareth Steenson back at the helm Exeter edged to a hard-fought win thanks to tries from Simon Alcott and James Phillips at a bitterly cold Rodney Parade.
Jason Tovey, back in the Dragons' starting line-up, booted the hosts into the lead after just six minutes and exchanged further penalties with Exeter fly-half Ignacio Mieres as the Welsh region edged into a 9-6 lead after 24 minutes.
With Exeter's Simon Alcott in the sin-bin, the Dragons surged into a commanding lead thanks to Faletau. The Wales World Cup star burst through the Chief's defence from his own 22 and crashed over following neat inter play with Tovey and Aled Brew.
Tovey kept the scoreboard ticking over to hand the hosts a 10-point advantage at the break but the Chiefs came storming back.
They made the perfect start when Alcott crashed over on 51 minutes. Steenson continued to chip away with penalties and Chiefs snatched the victory at the death when Phillips dived over following a dominant final quarter.