Manuel Pellegrini made it clear before the second leg that the tie was “not over” and during a first half that saw his Betis side take the game to United, the hosts were unlucky not to have found an opener.
Joaquín, now over the age of 41, clipped the post with a speculative 25-yard strike, before Juanmi saw a goal-bound strike blocked by United outcast Harry Maguire.
At the opposite end, Wout Weghorst, with the goal gaping, was unable to turn home Facundo Pellistri’s mishit strike, meaning, somehow, the game remained goalless at the break despite the open nature of the first half.
While they may have been forced to defend more than they might’ve expected, the visitors entered HT with their three-goal aggregate advantage just about intact.
In the end, it would matter little, as Rashford eventually broke the deadlock midway through the second half. Taking aim from range, the prolific forward nestled a thunderous right-footed strike into the far corner, all but securing United’s safe passage into the next round in the process.
Further chances came and went for United to add to their lead, but Marcel Sabitzer and Jadon Sancho were unable to show a clinical edge in front of goal.
Erik ten Hag will have been satisfied with his side’s performance which sealed a 4-1 aggregate victory though, as the Stretford-based outfit left Spanish soil unbeaten for the third time this season.
As for Betis, their European dream ends in rather limp fashion, while their wretched record at home stretches to four defeats from their last six matches.
Flashscore Man of the Match: Facundo Pellistri (Manchester United)
