Inter Milan dropped points in Serie A for the first time in more than two months as Atalanta held the league leaders to an entertaining 0-0 draw.
Tammy Abraham scored two goals as AS Roma put on a counter-attacking clinic to stun Atalanta with a 4-1 win in Bergamo on Saturday.
Atalanta made it six wins in a row in Serie A after coming from behind to earn a 2-1 victory at Hellas Verona on Sunday.
Villarreal reached the Champions League knockout stages as Arnaut Danjuma's double helped them to a 3-2 win at Atalanta.
The Champions League Group F clash between Atalanta and Villarreal was postponed on Wednesday due to heavy snow in Bergamo.
Napoli surrendered the lead to lose 3-2 at home to Atalanta on Saturday, dropping from first to third in the Serie A standings.
Juventus suffered another setback as they lost 1-0 at home to Atalanta after a Duvan Zapata goal on Saturday, with a fifth defeat in 14 games.
Atalanta's Luis Muriel came off the bench to equalise two minutes from time and snatch a 3-3 draw at Young Boys in a frenetic finish.
Cristiano Ronaldo saved Manchester United in the Champions League again as his stoppage time goal earned them a 2-2 draw away to Atalanta.
A federal investigation has opened in Italy into a number of transfers in Serie A, an Italian Football Federation official has said.
Udinese striker Beto's dramatic stoppage-time header earned his side a point in a 1-1 draw at Atalanta in Serie A on Sunday.
Cristiano Ronaldo scored a late goal as Manchester United mounted a second-half rally to beat Atalanta 3-2 in Champions League group-stage action.
Morale at Manchester United has taken a significant hit after Saturday's defeat to Leicester is the latest setback in a poor run of form.
AC Milan continued their impressive start to the Serie A season on Sunday, surviving a late Atalanta comeback to earn a 3-2 victory in Bergamo.
Atalanta maintained their good start in the Champions League after an opportunist goal from Matteo Pessina saw them beat Young Boys 1-0.
Inter Milan maintained their unbeaten record in Serie A with an entertaining 2-2 draw against Atalanta on Saturday that featured late drama.
Atalanta's Marten de Roon went to the club shop and offered to pay for jerseys with his name on the back. But nobody showed up.
Duvan Zapata's brilliant turn and finish earned Atalanta a battling 1-0 victory at Salernitana on Saturday.
A late Robin Gosens equaliser earned Atalanta a 2-2 draw at Villarreal on Tuesday as the Spanish side made their first appearance in 10 years.
Dusan Vlahovic scored two penalties to earn Fiorentina a 2-1 win away to Atalanta in Serie A on Saturday.
Young substitute Roberto Piccoli struck deep into stoppage time to earn Atalanta a last-gasp 2-1 victory at Torino.
Tottenham Hotspur have completed the signing of defender Cristian Romero from Atalanta, the club announced on Friday.