The Oklahoma City Thunder beat the Memphis Grizzlies, 131-80, in Game 1 of their Western Conference playoff series on Sunday, the fifth-biggest margin of victory in NBA postseason history. Jalen Williams scored 20 points and Chet Holmgren had 19 points and 10 rebounds. Oklahoma City, which finished the regular season with a league-best 68-14 record, looked every bit the part of an overall No. 1 seed. Oklahoma City's Shai Gilgeous-Alexander, the league's scoring champion with nearly 33 points per game, scored just 15. The Thunder still shot 50.5% from the field. Ja Morant scored 17 points for Memphis on just 6-for-17 shooting. Jaren Jackson Jr., who averaged just over 22 points in the regular season, scored four points on 2-for-13 shooting. Marvin Bagley III also scored 17, but the Grizzlies shot just 34.4% overall. There have been two 58-point playoff margins in NBA history: Denver beating New Orleans, 121-63, on April 27, 2009, and the Minneapolis Lakers beating the St. Louis Hawks, 133-75, on March 19, 1956. The Los Angeles Lakers beat Golden State by 56 (126-70) on April 21, 1973, and the Chicago Bulls beat the Milwaukee Bucks by 54 (120-66) on April 30, 2015. And now, a 51-point game — where the Thunder had it well in hand by early in the second quarter. This was Memphis' first playoff game under interim coach Tuomas Iisalo. He coached just nine NBA regular-season games before the play-in games. Game 2 is on Tuesday. Reporting by The Associated Press. Want great stories delivered right to your inbox? Create or log in to your FOX Sports account, follow leagues, teams and players to receive a personalized newsletter daily!