​San Francisco 49ers rookie defensive tackle Gracen Halton is playing like one of the NFL’s best run stoppers.Halton ranks third among all defensive tackles in run-stopping grade this season, according to Pro Football Network’s DT Impact metric. His 92.2 trails only Tennessee’s Jeffery Simmons (100.0) and Cincinnati’s Dexter Lawrence (94.2). That puts him just ahead of Dallas’ Quinnen Williams (91.9), Buffalo’s Deone Walker (90.1) and former 49er DeForest Buckner (87.7).Halton, a fourth-round pick at No. 107 overall out of Oklahoma, has been a steady presence in the middle. He has started five of six games and played 177 defensive snaps, or 44% of the 49ers’ total. He has 15 tackles and two sacks, and he forced and recovered a fumble for a touchdown.San Francisco’s defense has allowed 541 rushing yards on 150 carries, an average of 3.6 yards per attempt. That ranks seventh in the NFL in both rushing yards and yards per carry allowed. Opponents have scored only three rushing touchdowns against the 49ers, the fourth-fewest in the league. Last year, they ranked 11th in rushing yards allowed and 20th in yards per carry allowed, while giving up 13 rushing touchdowns.It’s a strong early return for a Day 3 pick who is sharing time in the D-line rotation and still making his presence felt.This article originally appeared on Niners Wire: 49ers rookie is helping solve major defensive issue