LOUDON, N.H. — Matt Kenseth pushed Kevin Harvick down the stretch and took the lead for good when the defending series champion ran out of gas Sunday at New Hampshire Motor Speedway in the second race of the Chase for the NASCAR Sprint Cup Championship. Kenseth advanced to the second round of NASCAR’s playoffs and gave Joe Gibbs Racing its fourth straight win. Harvick had the dominant car and led the most laps but a gamble to stretch his fuel to the end backfired and he faded to 21st.