Javier Pastore scored twice and Kevin 0, on Saturday at the Stade de la Mosson to go top of France's Ligue 1.
Gameiro opened the scoring in the 39th minute, and Pastore scored in the 43rd and 80th for his third and fourth goals of the season, as PSG extended its run to seven straight Ligue 1 matches without a loss.
Since losing its first game, PSG has five wins and two ties. Montpellier began the weekend atop the league, but lost for the second time and is one point off the pace of PSG, Lyon and Toulouse - all level on 17 points.
Lyon 3, Bordeaux 1
Lyon, France - Bafetimbi Gomis scored a brace to lift Lyon to a 3-1 win over Bordeaux on Saturday at the Stade de Gerland and into a tie on points with PSG and Toulouse for first place in France's Ligue 1.
Gomis scored in the 7th and 33rd minutes, and sits atop the scoring list with six goals through eight matches. Michel Bastos added the third goal for Lyon.
Anthony Modeste converted a penalty for Bordeaux, which has just one win.
Lille 1, Lorient 1
Lille, France - Kevin Monnet-Paquet scored in stoppage time as Lorient stole a point against Lille with a 1-1 tie at the Stade Lille-Metropole on Saturday in France's Ligue 1.
Joe Cole scored his first goal for Lille in the first half, but Monnet-Paquet volleyed home the equalizer in the closing minutes after Cole was taken off as Lorient extended its unbeaten streak to five games.
Lille, the defending Ligue 1 champion, is unbeaten in six straight.
Toulouse 1, Nancy 0
Toulouse, France - Umut Bulut scored in the 59th minute as Toulouse beat Nancy 1-0 on Saturday at the Stadium Municipal de Toulouse to earn a share of first place in France's Ligue 1.
Toulouse's lone defeat this season was against PSG, which along with Lyon also has 17 points through eight weeks. Nancy remained winless as it has just four points from four draws.
Caen 4, Evian 2
Annecy, France - Frederic Bulot and Kandia Traore scored in a four-minute span of the second half as Caen defeated Evian, 4-2, on Saturday at Parc des Sports in France's Ligue 1.
Cedric Barbosa scored twice in the first half for Evian, and M'baye Niang and Gregory Proment scored before halftime for Caen, which won its fourth of the season. Promoted Evian has just one win after eight games.
Nice 1, Dijon 1
Nice, France - Franck Djadjede scored in stoppage time as Nice managed a 1-1 draw with Dijon at Stade Municipal du Ray on Saturday in France's Ligue 1.
Benjamin Corgnet scored early in the first half for promoted Dijon, which has 10 points through eight matches. Nice is on six points from eight games.
Valenciennes 2, Marseille 1
Valenciennes, France - Jose Saez scored in stoppage time as Valenciennes tied Marseille, 1-1, on Saturday at the Stade Nungesser in France's Ligue 1.
Souleymane Diawara scored in the 16th minute for Marseille, which has just one win and seven points after eight matches. Valenciennes has six points.