Loyola Marymount kept it close in a tightly-contested first half before top-ranked Gonzaga caught fire.
Anthony Ireland led the Lions with 19 points, but the Bulldogs picked it up in the second half and advanced to Monday's West Coast Conference championship with a 66-48 win Saturday night.
The Lions (8-23, 1-16 WCC) trailed 27-26 at the end of a hard-fought first half. With 1:10 left till halftime, Loyola took the lead on Marin Mornar's layup to make it 26-25. But the Bulldogs' Sam Dower hit a layup with one second left to give No. 1 seed Gonzaga (30-2, 17-0 WCC) a 27-26 lead as the half ended.
The Lions shot a dismal 7 of 29 (24.1 percent) from the field in the second half and went 1 of 10 on 3-point attempts.
''We haven't shot the ball well from outside,'' Lions coach Max Good said. ''We have to shoot better from the perimeter. (Gonzaga) had a little trouble guarding us man to man. They were better in the zone. I don't think (the Gonzaga fans) were a factor.''
''They are very well-coached. They are a tremendous team,'' Good said. ''If you want to be the best you have to beat the best.''
There were four ties and eight lead changes in the first half.
LMU was 8-for-20 from the field and 4-for-10 on three-pointers. The ninth-seeded Lions also went 6-for-10 at the free throw line. Gonzaga was 9-for-24 from the field in the first half. They were 1-of-7 from 3-point range and hit eight of their 10 free throws.
Elias Harris had 21 points and eight rebounds to lead Gonzaga. Bidding for a top seed in the NCAA tournament, the Bulldogs advanced to play for the league championship Monday night.
Challenged in the first half by a team that went 1-15 in WCC play this season, Gonzaga turned up the defensive intensity and opened the second half on a 19-5 run to seize momentum. Gonzaga outscored the Lions 39-22 in the second half.
Kevin Pangos added 14 points and Kelly Olynyk had eight points and eight rebounds for the Zags.
The Zags turned around their horrendous first half shooting with a blistering 11 of 22 from the floor, including 4 of 7 from long range.
The Lions forced 45 turnovers - and committed only 32 - in their first three games of the tournament, but last night came up against a Gonzaga team much more disciplined than their previous foes, and bit more tenacious on defense. And while LMU committed 16 miscues, compared to Gonzaga's 13, the Bulldogs outscored the Lions 19-6 off turnovers.
Gonzaga also outrebounded the Lions 38-31, while outscoring them in the paint 28-12.
The Zags' domination came in the second half. The Lions held Gonzaga scoreless early on, for a little more than three minutes, while going on a 9-0 run to take a 14-9 lead. The Bulldogs returned the favor by going on a 7-0 run, while holding Loyola scoreless for a bit less than three minutes, to take a 16-14 lead.
From there the two continued to play back and forth while neither built a margin bigger than two points, with the lead changing hands seven times over the final 4:16 of the half.
The Lions, who posted one win in the first two months of the calendar year, tripled that figure in the WCC tournament with three straight wins to get to the semifinals.
LMU knocked off No. 8 Portland 65-54 on Wednesday to wedge its way into the bracket. The Lions upset No. 5 San Francisco 61-60 in overtime on Thursday then stunned fourth-seeded Santa Clara 60-58 on Friday.
The Bulldogs, who earned the WCC's top seed for the 13th time, were the first team to go 16-0 in the league in the two years of the 16-game format. It was their fourth undefeated West Coast campaign, also going unbeaten in 2004, 2006 and 2009, when the conference played a 14-game schedule, prior to BYU joining the conference.