LAKE BUENA VISTA, FLORIDA - AUGUST 23: Jayson Tatum #0 of the Boston Celtics speaks with Joel Embiid #21 of the Philadelphia 76ers after the game in Game Four of the first round of the playoffs at The Field House at ESPN Wide World Of Sports Complex LAKE BUENA VISTA, FLORIDA - Kemba Walker scored 32 points and the Boston Celtics pulled away in fourth quarter to complete a first-round series sweep of the Philadelphia 76ers 110-106 on Sunday.Jayson Tatum added 28 points and had a playoff career-high 15 rebounds for Boston, which advances to Eastern Conference semifinals and a meeting with the winner of the first-round matchup between Toronto and Brooklyn.Boston’s win marks the first sweep in 15 playoff series meetings between the teams.