Tammy Abraham has scored six Serie A goals so far this season
Juventus gave their hopes of reaching the Champions League a boost on Saturday after a hard-fought 2-0 win at Bologna following Roma's thumping 4-1 victory at fancied Atalanta.
Goals in each half from Alvaro Morata and Juan Cuadrado ensured that Juve joined Roma at five points from the league's top four positions.
Massimiliano Allegri's side came away with the three points following a dogged performance at a ground which has proved tough terrain for some of Serie A's leading sides and was enveloped in thick fog for almost the entire match.
Juve sit a sobering 12 points behind champions and league leaders Inter Milan, who crushed Salernitana 5-0 on Friday, but while a title challenge is almost certainly out of the question this year a place in Europe's top club competition is something they can fight for.
"When we play with this attitude, with determination and skill these are the results we get," said Leonardo Bonucci to DAZN.
"We can't afford to lose any more ground on the teams in front of us so this was a big win."
How far Juve sit from their target come the end of the weekend depends on how injury-hit Napoli fare at fellow title-chasers AC Milan on Sunday night.
Luciano Spalletti's team are fourth, a point away from Atalanta, but can go second with a win in northern Italy.
Morata pinched the lead for Juve on the break in the sixth minute, the Spain forward finishing after launching the attack and blasting home following a give-and-go with Federico Bernadeschi.
Juve were on the back foot for much of the match and home fans were ready to celebrate an equaliser in the 22nd minute when Mattias Svanberg lined up a bicycle kick from Mark Arnautovic's deflected cross, but the Swede's acrobatic effort flashed just wide.
After defending for the best part of 25 minutes from the start of the second half, Colombian Cuadrado sealed the win with a long range strike which took a wicked deflection Aaron Hickey.
England international Abraham opened the scoring with less than a minute on the clock in Bergamo and, late on, rounded off coach Mourinho's biggest win since he returned to Serie A with a deft first-time strike to take his league tally to six for the season.
"What a win, what else can I say? A lot of people doubted us today but this is by far one of the best wins we've had this season," said Abraham to DAZN.
Nicolo Zaniolo, with his first Serie A goal since July last year, and Abraham's countryman Chris Smalling also netted in Roma's first win against one of Italy's top teams this campaign, denting Atalanta's burgeoning title hopes.
Gian Piero Gasperini's third-placed side are six points behind Inter after being defeated by a Roma team whose goals came from five shots on target after having less than 30 percent possession and no corners.
The match turned during four minutes midway through the second half in which Atalanta had a leveller ruled out by VAR for Jose Luis Palomino straying offside after challenging for Duvan Zapata's flick with Bryan Cristante and Smalling then poked home Roma's third.
The decision to rule out the hosts' leveller infuriated Gasperini who raged to DAZN that the referee told him a Palomino goal had been ruled out even though the Argentine had not, in fact, touched the ball.
"If Palomino didn't touch the ball, then why is it offside? If Cristante got the ball, then what difference does it make?" he asked.
In Saturday's late game Cagliari try to get out of the relegation zone when they host Udinese in Sardinia.