Roma's hopes of a record-extending 11th successive Italian Serie A victory were thwarted Sunday by a team that hadn't won in six matches.
Torino's streak was stretched to seven by the 1-1 draw, which gave Turin rival Juventus a boost in its bid to win a third successive title.
The result left league leader Roma three points clear of Juve and Napoli, who both won on Saturday.
The capital club, seeking a first title since 2001 under the guidance of new French coach Rudi Garcia, seemed on course for another routine win when Dutch midfielder Kevin Strootman fired a 28th-minute opener.
But Torino hit back in the 63rd minute through striker Alessio Cerci, whose eighth league goal this season -- the second best behind Fiorentina's Giuseppe Rossi -- moved his team up to 12th place.
It was only the second goal scored against Roma in the top flight this season, the other being by Parma in September.
The visiting side, which had the only 100% record in the major European leagues, again missed the attacking presence of captain Francesco Totti and Ivory Coast forward Gervinho, both sidelined by injury.
Inter Milan reclaimed fourth place with a 3-0 win at Udinese that kept Walter Mazzarri's team above Verona on goal difference.
Verona beat Cagliari 2-1, while Roma's seventh-placed city rival Lazio lost ground with a 2-0 home defeat by Genoa.
In France, former Roma coach Claudio Ranieri suffered his first Ligue 1 defeat this season with Monaco, which lost 2-0 at Lille.
Lille climbed above the principality club into second place behind champion Paris Saint-Germain, which has a two-point advantage following Friday's 4-0 win over Lorient.
Nolan Roux scored both goals to inflict Monaco's second successive reverse, having also lost in the League Cup in midweek.
In Spain, Atletico Madrid kept the pressure on La Liga leader Barcelona with a 2-0 win at home to fifth-placed Athletic Bilbao.
Diego Costa joined Cristiano Ronaldo at the top of the scoring charts with his 13th goal this season, while strike partner David Villa added the other -- his sixth since leaving Barca.
The victory put Atletico a point behind the unbeaten champion and five clear of third-placed city rival Real Madrid, which struggled to a 3-2 win over bottom club Rayo Vallecano on Saturday.
Valencia moved into the top half of the table with a 1-0 win at Getafe, while Malaga climbed clear of the relegation zone with a 3-2 victory at home to third-bottom Real Betis.
In England, Tottenham and Everton both failed to claim second place in the Premier League after playing out a goalless draw.
Visiting Spurs moved up to fourth, on goal difference behind Liverpool and Chelsea, and five points adrift of London rival Arsenal.
It left Everton a point further back in seventh, below Manchester City and Southampton.
Tottenham goalkeeper Hugo Lloris played the last half an hour after receiving a heavy blow to the head which required nine minutes of injury-time to be added. The France international refused to go off the pitch despite medical advice.
"Hugo still doesn't recall everything about the incident," Spurs manager Andre Villas-Boas said.
"I made the call to keep him on the pitch because of the signs he was giving. The saves he did after the incident proved that right."
Promoted Cardiff won the first Welsh derby to be played in the EPL, triumphing 1-0 against Swansea -- whose former defender Steven Caulker headed the only goal.