After enjoying a successful spell at Fulham, Silva was chosen as the replacement for Jose Mourinho at Benfica when the latter left to take charge of Real Madrid for the upcoming season.
He didn't have long to get settled before his first match of meaning, with the club from Lisbon having to contest the qualifying rounds of the Europa League due to their third-place finish domestically last season.
The draw pitted them against Swiss side St. Gallen, and despite being heavy favourites, Silva's side suffered a 2-1 defeat in the first leg.
The underdogs dominated the game from the off, with Aliou Balde going close in the second minute and again in the 12th.
It was third time lucky for the striker, who then opened the scoring with a stunning finish, firing the ball into the top of the far corner from the tightest of angles.
That looked to be the wake-up call that Benfica needed, with them levelling things up just seven minutes after conceding and just one minute before the break courtesy of Rafa Silva, who made no mistake after being put through on goal by Vangelis Pavlidis.
Marco Silva's side enjoyed more control of the game after the interval, seeing more of the ball and looking more likely to score for much of it. However, they weren't able to create much in the way of clear-cut chances.
With 10 minutes to go, Benfica probably would've been relatively happy to head back home for the second leg on level terms, but disaster struck when Tom Gaal headed in a free-kick at the far post to put St. Gallen back ahead.
The Portuguese giants were unable to find an equaliser, and Silva now must lead them to victory in the second leg to avoid an early Europa League exit and a disastrous start to his tenure.
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