Last-placed Atalanta beat Serie A leader Juventus 2-0 and Siena stunned AS Roma 2-1 Friday in first-leg, third-round matches of the Italian Cup.
Also on Friday, Sampdoria scored two late goals to overcome second-division Torino 2-0 at Turin's Stadio delle Alpi.
The setbacks of La Juve and Roma, which started several second-tier players, seemed to indicate fading interest of the major clubs for the annual knockout tournament, which once awarded a berth in the European tournaments.
"If a place in the Champions League were at stake, no doubt that the interest for the Italian Cup would be boosted," Juventus coach Fabio Capello said.
At Bergamo, 19-year-old midfielder Andrea Lazzari scored two second-half goals to earn Atalanta a prestigious home win.
The Bergamo club, winless in 12 Serie A games, is last in the 20-team Italian league with seven points.
Lazzari, who was developed on Atalanta's junior teams, opened the scoring in the 58th minute after a save by Juventus goalkeeper Antonio Chimenti.
The midfieldcer was denied a goal by Chimenti in the 63rd, but Lazzari struck again with a shot just under the crossbar in the 75th.
Juventus, which has an 11-1-0 record and leads the Serie A by six points, played without regular strikers Zlatan Ibrahimovic and Alessandro Del Piero and failed to score for the first time in the last 22 matches.
"At last we captured a long-sought win," Atalanta coach Andrea Mandorlini said. "It came on an important night. Juventus is very strong also when it fields reserve players."
At Stadio Olimpico in Rome, Tore Andre Flo scored twice on headers, including the winner in the 87th minute to lead Siena.
It was a further blow for AS Roma, which has been eliminated from the European Champions League and is in 15th place in the Serie A after finishing second to AC Milan last season.
Fans jeered Roma players following the unexpected home loss that added to five defeats in 12 league games.
Flo, often relegated to Siena's substitute bench, produced his best performance of the season, repeatedly troubling the Roma defense.
The Norwegian striker scored in the 37th with a close-range header and had one goal disallowed for a dubious offside in the 42nd before scoring the winner with three minutes remaining.
Defending champion Lyon drew 10-man Paris Saint-Germain 0-0 and extended its lead at the top of the French first division to four points on Friday.
Lyon, undefeated in the league since May, has 33 points after 15 rounds. Lille was second place with 29 points, and Auxerre third with 25.
In Friday's other match, teenager Jeremy Menez opened the scoring and Wilson Oruma and Araujo Ilan added further goals as Sochaux won 3-1 away to Monaco.
PSG's Colombia defender Mario Yepes was sent off by referee Alain Sars for a second yellow card after chopping down striker Sylvain Wiltord in the 23rd minute.
PSG coach Vahid Halilhodzic reacted furiously and was restrained by striker Pauleta as he shouted at Sars face to face. Sars expelled Halilhodzic and his assistant coach from the bench.
Against Marseille two weeks ago, defender Sylvain Armand was sent off in the first half but PSG went on to win 2-1.
Wiltord missed an early chance for Lyon when his shot was pushed away by Lionel Letizi and the visitors had most of the first-half play without creating further opportunities.