Slim Shadey led all the way in winning the $150,000 San Marcos Stakes by a length on Saturday at Santa Anita, giving Hall of Fame jockey Gary Stevens his first stakes victory since his comeback began on Jan. 6.Slim Shadey ran 1 1/4 miles on the turf in 1:59.17 and paid $13.40, $7 and $5.40.Stevens, who turns 50 next month, had two wins and 11 seconds from 33 mounts coming into the race, his first aboard the 5-year-old gelding."When I worked him the other morning, it seemed like the horse was happy," Stevens said. "I just wanted to stay out of his way and let him be his own man, and that's exactly what he is. I haven't had a lot of horses sprint home like he did in the last 30 years going a mile and a quarter, so it was a great feeling."Interaction returned $5.20 and $3.60 as the 7-2 favorite, while All Squared Away was another 2 1/4 lengths back in third and paid $4.80 to show.The victory, worth $90,000, increased Slim Shadey's career earnings to $613,850, with five wins in 26 starts.