SPOKANE - Steven Gray was lights out from behind the arc, making six 3-pointers in the first half, as Gonzaga beat Eastern Washington 86-57 on Tuesday night.

Gray's 18 points helped the Bulldogs build a 49-20 halftime lead. His teammates carried the scoring load in the second half, as Gonzaga led by as many as 42 points.

Robert Sacre and freshman Mathis Monninghoff scored 13 apiece and Sam Dower added 11 for Gonzaga (4-2). Monninghoff made all five of his shots, including three 3-pointers. The Bulldogs shot 57.9 percent from the field and made 11 of 16 3-pointers.

"It makes my job extremely easy to post up because guys aren't sagging in," Sacre said. "They have to worry about Steven outside shooting the 3, and Monninghoff. It's a great thing to have those guys shooting lights out."

Eastern Washington (1-5) was led by Jeffrey Forbes' 18 points, and Kevin Winford added 11. The Eagles shot 33.9 percent, made 7 of 18 free throws, had 10 assists and were forced into 21 turnovers.

The Eagles have lost 30 of the last 31 games against their Spokane County neighbor, including 23 straight.

Eastern Washington hit consecutive 3-pointers to cut the lead to 54-26. But Monninghoff scored seven consecutive points during a 13-6 run to build a 67-32 lead.

Gonzaga opened the game on a 14-5 spurt and made its first seven attempts from behind the arc. The Bulldogs were 8 of 12 from the field in the first 11 minutes.

Eastern Washington struggled from the floor, making 3 of 12 shots in the first 8 minutes. The Eagles were without guards Glen Dean and Cliff Colimon and forward Rashano McCrae.

"When you're playing without a point guard, it's pretty tough," coach Kirk Earlywine said. "You have to have a quarterback out there. We've got all kinds of guys trying to do things that they don't normally do."

Gray made three consecutive 3-pointers during a 15-0 run to push Gonzaga's lead to 38-12 with 4:08 left. Gray finally missed a 3-pointer at the 3:52 mark after making his first six.

"Steve was hot and feeling it," Gonzaga coach Mark Few said. "They did a nice job of finding the hot hand."

Gonzaga's biggest first-half lead was 31 points after making nine 3-pointers and holding the Eagles to eight field goals.

Gonzaga sophomore forward Elias Harris did not play. He has been battling an Achilles' tendon injury. Manny Arop replaced Harris in the starting lineup.

"He has just not been able to practice since we returned from Kansas City," Few said. "He's tried to loosen it up, and it just feels really, really tight."

Gonzaga fell out of the Top 25 this week after losing to No. 5 Kansas State 81-64 and beating Marquette 66-63.

Gonzaga faces No. 20 Illinois on Saturday in Seattle, then travels to in-state rival Washington State and then to No. 25 Notre Dame.