EVANSTON—Alex Olah scored 21 points to lead Northwestern over Southern Illinois Edwardsville 81-56 on Saturday.Aaron Falzon added 17 and Bryant McIntosh chipped in with 11 for Northwestern (7-1), which has won four straight. The Wildcats shot 51.7 percent overall, made nine 3-pointers as a team and got five 3-pointers from Falzon. The Wildcats were boosted 12 first-half points from Olah and have their best eight-game start since 2011-12, when they also began 7-1.Playing its first game after beating Virginia Tech 81-79 in overtime Tuesday as part of the Big Ten/ACC Challenge, Northwestern had little trouble with the visiting Cougars and led 35-26 at halftime despite shooting just 38.7 percent from the field during the opening 20 minutes.The Cougars (1-7) lost their seventh straight since opening the season with a 79-70 win over Arkansas State. SIUE also fell to 0-4 on the road, and is in the middle of a three-game trip away from home.The Wildcats, who won’t play again until Dec. 13, took their first 10-point lead at 23-13 with 6:23 left in the first half on a layup by Sanjay Lumpkin. Northwestern built its advantage to 29-15 with 4:25 remaining on a 3-pointer by Falzon, a shot notable because Falzon was playing without his right shoe.Northwestern was never really threatened during the second half. An Olah basket with 5:49 left in the second half put Northwestern ahead 65-44 and gave the Wildcats their first lead of at least 20 points.Burak Eslik scored 13 points for SIUE, which hasn’t lost by single digits since a 77-74 loss to Campbell on Nov. 24. Following that defeat, the Cougars have lost by at least 13 points in their following four contests.The Cougars are in the middle of a stretch of four games in seven days.Saturday’s game was SIUE’s first against a team from one of the five power conferences.The Wildcats improved to 5-0 all-time against SIUE, and 2-0 against the Cougars since their 2011 transition to Division-I. . Tuesday night’s win at Virginia Tech was the Wildcats’ fifth OT game over the past two seasons.Northwestern hosts Chicago State next Sunday.