Czech side Plzen leapfrogged BATE Borisov into third place in Group H with their hard-fought Champions League win putting them one step closer to claiming a place in the Europa League.
Marek Bakos' goal just before half-time proved to be the difference in a match which was shrouded in fog at the Dinamo Stadion in Minsk.
With Barcelona and AC Milan doing battle for top spot in Group H, neither BATE not Plzen can progress to the knockout stages, but there was plenty at stake as third place in the group offers the consolation of a Europa League spot.
The win for Plzen was their first Champions League victory in their history and they moved two points clear of BATE, who must now defeat Barcelona at the Nou Camp if they are to deny the Czech side third place.
The game began a great pace with both sides creating plenty of chances.
Aleksandr Gutor made a terrific save in the second minute when Vaclar Pilar raced into the area and struck towards the bottom corner.
Plzen midfielder Pavel Horvath then took the first corner which Daniel Kolar headed over the bar as the visitors had the best of the early exchanges.
BATE almost went in front after a great attacking move only for striker Renan Bressan's shot to go wide in the 10th minute before Bakos saw his header caught by Gutor at the other end.
Plzen's Milan Petrzela then had his 20-yard shot blocked by Marko Simic as both sides struggled to find the breakthrough.
Gutor tipped another shot by Petrzela over the bar before Plzen won their eighth corner of the match to test the BATE defence again, however the chance went begging.
And it was Plzen who went in front when Petrzela raced into the area and pulled the ball back for Bakos, who poked home from close range in the 42nd minute.
It was the striker's sixth goal in seven games in all competitions and arguably his most important, as the score all but ensured Europa League football for his side.
However, after the break, the hosts almost hit back when Maksim Bordachev's shot narrowly missed the right post after Bressan took a short corner.
Bressan had a shot of his own blocked from a 30-yard free-kick which was perfectly placed to trouble Cech but the Brazilian fired straight into the Plzen wall.
As the foggy conditions worsened, BATE's chances of pulling level diminished, and Plzen held on to claim a historic victory.