Gabon international Denis Bouanga scored a hat-trick as Los Angeles FC put one foot in the quarter-finals of the CONCACAF Champions League on Thursday with a 3-0 first-leg away victory over Costa Rica's Alajuelense.

Bouanga fired the Major League Soccer champions to the brink of the last eight with a flurry of goals in the second half at the Alejandro Morera Soto Stadium outside San Jose.

Bouanga's treble came tinged with relief after the winger somehow missed an open goal in the first half from five yards out as Los Angeles chased a breakthrough.

Despite LAFC dominating for long periods in the first half they were kept at bay by determined defending from Alajuelense, who created few chances of their own at the other end.

The breakthrough finally came just after half-time when Los Angeles fullback Ryan Hollingshead bombed down the right flank and whipped in a low cross that Bouanga jabbed home for 1-0.

Former Mexico international Carlos Vela almost made it 2-0 soon afterwards, forcing an acrobatic diving save from Leonel Moreira in the Alajuelense goal.

Los Angeles bided their time however and effectively killed off the game in the 70th minute with a second goal that was almost a carbon copy of the first.

Hollingshead once again accelerated into space down the right hand side and beat the covering defender before drilling another low ball across the six-yard area for Bouanga to steer home.

LAFC's young Croatian substitute Stipe Biuk almost made it 3-0 in the 83rd minute after bursting into the area following a clever one-two, but his shot was well-saved by Moreira, who also denied Bouanga a hat-trick two minutes later with a reflex save.

But Moreira could do little to stop Bouanga's third, a rasping angled shot from just inside the area which flew high into the far corner to make it 3-0.

LAFC – beaten finalists in the competition in 2020 -- are bidding to become only the second MLS team to win the CONCACAF Champions League in the modern era following the Seattle Sounders' breakthrough win in the competition last year.

In Thursday's other last-16 game, Honduras's Motagua were held to a 0-0 draw at home to Pachuca of Mexico.