Benjamin made his debut with the London Symphony Orchestra on Thursday 26 January, performing Brahms' Piano Concerto No. 1 conducted by Alpesh Chauhan. In a review for Bachtrack, Alexander Hall commented:

“the chamber-like delicacy of much of Grosvenor’s playing, ably supported by the LSO’s wind soloists and horn section, made this a reading of considerable subtlety, with the rhapsodic elements in the development section benefiting from a clarity of tone and phrasing.”

Geoff Brown at The Times published a 4* review, adding:

“[A] young British luminary sat bolt upright at the keys for Brahms’ Piano Concerto No. 1 … Never a flighty or showy artist, Grosvenor managed to make the solo part’s fierce unison statements and pensive passages even more grandiose than usual.”

Finally, Classical Source's Ates Orga noted:

“Grosvenor held his own. At times achieving a delicacy and finesse, a whispered phrasing-off, a weighting of melody, inner voicing and chords one might expect more from a recital or studio context, he reached the poetic heights in the Adagio, the closing trills and final ensemble dissolving ethereally … You could hear a pin drop. The great F-major double-octave clarion call of the first movement, the Beethovenian stamp and canter, the glittering cascades of the Finale, the two closing fantasia-cadenzas showed another side – bold, grand and authoritative, prepared to play the hall but with quality, tone and taste at a premium. There was much to satisfy.”