Arsenal took a huge step towards qualifying for the quarter-finals of the Champions League with a 4-0 win over OH Leuven in the first leg of their play-off clash.

Frida Maanum was on target either side of Olivia Smith's 37th-minute strike, while Alessia Russo rounded off the scoring in the second half as the Gunners proved too much for their Belgian opponents.

The defending champions took the lead after 22 minutes, with Maanum stooping to head in Caitlin Foord's cross, before Smith doubled the visitors' advantage soon after as she swept home from Chloe Kelly's low centre.

Victoria Pelova went close to adding a third shortly after the break as her left-footed strike went narrowly wide of the right post, though Maanum combined with Foord again as the former tapped in from close range.

Daphne van Domselaar was called into action shortly after the hour mark, tipping over a long-range effort from Alixe Bosteels, though that was Leuven's only shot on target.

Russo, who got an assist when these two sides met in the league phase, then applied the simplest of finishes as she reacted quickest to a deflected cross from the right and guided the ball past the defenders on the line.

Data Debrief: Smith goes from strength to strength

It was a dominant display from Renee Slegers' side in the end as they produced 2.67 expected goals (xG) from 19 shots to Leuven's meagre 0.14 from five attempts.

And Smith's goal was a deserved reward for her performance. The 21-year-old registered the most shots in the match (five), most touches in the box (16), completed the most dribbles (6/10) and won the joint-most duels (eight – tied with team-mate Laia Codina).

And the Gunners will take plenty of hope knowing that all 153 of the teams to win the first leg of a Women's Champions League knockout stage tie by 3+ goals have gone on to win the tie.