EAST RUTHERFORD, N.J.—It’s been said defenses win championships, and nobody in the NFL might be playing better D right now than the Dallas Cowboys. DeMarcus Lawrence forced a fumble and made two other big plays that led to 15 points and the Dallas defense forced four turnovers for the third straight game Sunday. The Cowboys inched closer to their first playoff berth since 2018 with a 21–6 win over the New York Giants. “We’re the best defense,” a blunt Trevon Diggs said after picking up his league-high 10th interception of the season, one shy of the team record set by Everson Walls in 1981. Lawrence said the defense is the best he has played on in his eight seasons. “It’s amazing just to be on a team with a strong defense,” he said. “It doesn’t get any better than that.” This has been a strange season for the Cowboys (10–4), …