Port Conway Lane, a 13-year-old gelding who won his first race at Timonium in 1971, came from far back to win the second race at Laurel Race Course yesterday under Bill Passmore.

The victory, in a $4,000 claiming race, was the 49th for the white son of Bold Commander and grandson of Bold Ruler. He has started 226 times and has earned $417,181.

Trainer King T. Leatherbury had Port Conway Lane as a yearling and raced him until 1977, when he was claimed. Leatherbury reclaimed him last August and yesterday's win was the horse's third of the year.

A smiling Leatherbury said after the race yesterday: "I had him as a youngster and kept tabs on him after we lost him some years ago. He's won five stakes. One of the reasons I dropped him into a claimer some five years ago was that he had a tumor in the middle of his forehead. After he ran for other people for several years and survived, I figured that the tumor had to be harmless. He still has the tumor and it's as big as a golf ball . . . Win No. 50 is what we're shooting for."

Port Conway Lane has won on 10 tracks and his ownership has changed 12 times. Leatherbury estimates the gelding's age is equivalent to "60 years in human terms."

In yesterday's race, Port Conway Lane's winning time was 1:13 1/5 and the winning mutuel was $4.80.

Mio Host, the second-place finisher who is 12 years old, completed a 5-6 exacta worth $38.20. Coupled with Barn Builder, the upset winner in the first race, Port Conway Lane completed an 8-5 daily double worth $160.40.

The victory yesterday put Port Conway Lane's earnings for the year over $14,000. No one took him for the $4,000 claiming price.