Binocular was gifted the lead after Ruthenoise's error
Champion hurdler Binocular won the Contenders Hurdle at Sandown under Tony McCoy but had to work for his victory.
Sent off the 1-10 favourite, he won by one and three quarter lengths from the 50-1 chance Ruthenoise, who made a mistake at the final flight.
Binocular, trained by Nicky Henderson, had not appeared at his best when winning the race a year ago, but triumphed at Cheltenham in March.
Meanwhile, stablemate Oscar Whisky won the Welsh Champion Hurdle at Ffos Las.
Afterwards, champion jockey McCoy said his mount was not as impressive as on his last victory at Kempton last month.
Binocular remains favourite for a repeat Champion Hurdle win although was eased slightly by some firms.
"He was probably not as impressive today as at Kempton (Christmas Hurdle) but it's hard to judge in a race like this," said BBC Sports Personality of the Year McCoy.
"I don't think he jumped as well as he can today, but with just three other horses you are being careful in case one falls or something like that.
"He was more impressive at Kempton, but you can't go on what he did here in a race like this.
"He seems in good form, he's progressing and hopefully we will get him there (Cheltenham) the same as last year."
Meanwhile, the Alan King-trained Medermit just held off the fast-finishing Captain Chris to win the Scilly Isles Novices' Chase at Sandown.