Altior and Native River both won at Newbury on Saturday as they continue to prepare for big races at next month's Cheltenham Festival.
Altior, ridden by Nico de Boinville, won the Betfair Exchange Chase, easing past Politologue after the final fence.
The 1-3 shot, trained by Nicky Henderson, is favourite for the Queen Mother Champion Chase at Cheltenham.
Gold Cup contender Native River led from the front to become the first horse to win the Denman Chase twice.
It was Native River's first race since finishing third in last year's Cheltenham Gold Cup but the Colin Tizzard-trained horse was 8-11 favourite on his comeback.
Under the guidance of champion jockey Richard Johnson, the eight-year-old set the pace and was never troubled as he won by 12 lengths.
Tizzard said: "It was ideal preparation for the Gold Cup and as long as he's OK in the next 10 days, the dream is still alive.
"He's a good jumper and when Richard asked he went away almost effortlessly. He's such a good horse."
Fellow Gold Cup horse Cloudy Dream was second, with Saphir Du Rheu last of the three on his first start since falling in the Grand National last April.
Altior's comeback win was hailed as "perfection" by trainer Nicky Henderson.
The eight-year-old's four-length victory extended his unbeaten run over jumps to 12 as he won the Grade Two contest for the second successive year.
"We knew he was in fantastic form," said Henderson. "He has so many gears. He just has class, it is just pure class and he is very good."
Amy Murphy picked up the biggest win of her training career when Kalashnikov edged to victory in the Betfair Hurdle.
Ridden by Jack Quinlan, the 8-1 joint favourite, spent much of the two-mile race in the middle of the field but battled into the lead in the run to the final flight and held on to beat Bleu Et Rouge.
BBC horse racing correspondent Cornelius Lysaght
Altior was simply fabulous in his first race since April; having bided his time during the race, in just a couple of strides, the horse swept aside the very much in-form - and race-fit - Politologue.
As potential arch-rival Douvan is only 50:50 to run, it is hard to see what can beat Altior in Cheltenham's Queen Mother Champion Chase, for which the best odds, 11-10, strike me as more than fair.
Also making a terrific seasonal comeback, after a ligament problem, was Native River as he is aimed at the Gold Cup.