Shishkin and Energumene remain on course for a mouthwatering clash at Ascot after both horses featured among the declarations for Saturday's SBK Clarence House Chase.
After well documented issues in the autumn, Nicky Henderson's Shishkin made a spectacular return to action in the Desert Orchid Chase at Kempton last month.
The Sholokhov gelding is a hot favourite to extend his unbeaten record over fences to seven in this weekend's feature event, but in Energumene he faces a new and serious rival.
Since finishing third in a Navan bumper on his debut, the eight-year-old has won each of his seven starts for Willie Mullins and is five from five over fences.
He looked set to meet Shishkin in the Arkle at Cheltenham last March after a dominant display in the Irish equivalent, but a setback ruled him out of the Festival.
Energumene recovered in time to win by 16 lengths at the Punchestown Festival, though, and looked as good as ever on his seasonal reappearance in the Hilly Way Chase at Cork in early December.
Due to the profile of the top two in the market, last year's winner First Flow will be a big price to successfully defend his crown for Kim Bailey.
The 10-year-old is a high-class horse in his own right, as he proved once again when lifting the Peterborough Chase at Huntingdon on his only previous start this term.
With Paul Nicholls deciding against running Tingle Creek runner-up Hitman, the field is completed by Dan Skelton's outsider Amoola Gold.
The nine-year-old has won at Ascot twice before, but has plenty to find on official ratings with his three rivals.
Retired jockey Barry Geraghty was on board Moscow Flyer for his memorable battles with Azertyuiop and Well Chief, as well as riding the incomparable Sprinter Sacre, so knows a thing or two about two-mile chasers.
However, he is finding it hard to split the big two.
"I thought Shishkin was better than ever at Kempton but Energumene…we haven't seen the best of either horse yet," he said.
"I think this is the best match up we've seen since Moscow and Azertyuiop all those years ago.
"There's only four runners, but with Kim Bailey's horse who won it last year and Energumene running they won't be messing about.
"It will be brilliant race and I can't wait to watch it. It will be a proper race, a real proper one."