Mr. Frisk, Amateur Jockey Capture Grand National

LIVERPOOL, England — Racing journalist Marcus Armytage on Saturday became the first amateur jockey to win the 4 1/2-mile Grand National steeplechase race since 1982.

Riding 16-1 shot Mr. Frisk, he ruined the 70th birthday celebrations of Arthur Stephenson by withstanding a late challenge from the trainer’s horse, Durham Edition.

Armytage and Mr. Frisk looked sure to be caught by Chris Grant and the 9-1 shot as they closed two fences from home.

But the winning partnership, never out of the first three, dug deep for one final effort and it paid off as they squeezed home by three-quarters of a length in a course record of 8 minutes 47.8 seconds, beating Red Rum’s 1973 time by more than 14 seconds.

Mr. Frisk won $113,000 for Lois Duffey, the 83-year-old American owner who had a horse participating in the Grand National for the first time, and paid $27 for a $1.60 bet.