Celtic boss Neil Lennon was justifiably proud with the performance and the spirit of his side as they produced a first-ever away win in the group stages of the UEFA Champions League.
The victory sees the Scottish champions sitting unbeaten with four points from their opening two Group G games ahead of back-to-back clashes with Barcelona.
While Lennon will be emphasising his side must take it game-by-game as they seek to progress from the group, this win will give his troops great confidence for the fight to reach the knock-out phase.
The Hoops had to do it the hard way though - withstanding sustained early pressure before Gary Hooper's 12th minute goal - and then battling back from 2-1 down to win.
Former Scunthorpe striker Hooper emphatically showed he can mix it at this level, producing an outstanding display as he led the line in the hostile Luzhniki Stadium.
The striker worked his socks off up front and was a constant threat to the Russian side, showing many facets to his game.
Firstly, there was his goalscoring prowess when getting ahead of his marker and notching the opener with a deadly first-time shot. Then he demonstrated his strength and awareness when Georgios Samaras stepped over the ball, which he collected before turning his marker and setting up James Forrest to shoot for the second goal. And his speed contributed to the crucial sending-off of Juan Insaurralde, who pulled Hooper down as he raced through on goal.
Celtic took full advantage of their numerical superiority as Lennon produced a great tactical switch, bringing off Victor Wanyama in the 70th minute and replacing him with James Forrest.
Forrest produced an immediate impact, with his shot being deflected in for Celtic's equaliser, while he proved a real livewire down the right flank which the Spartak defence struggled to contain.
Lennon had also restored Samaras to the Celtic starting XI. While the Greece striker was not at his best up front, he produced when it mattered most in heading home at the death to seal the famous win.
While proud and delighted, the Celtic boss will not be resting on his laurels. In particular, his side were exposed twice either side of the interval and he will want his defence to tighten up as Barcelona will be ruthless in exposing any weaknesses when the two sides meet next.