Argentine striker Lisandro, who has been erratic this season, produced a fine performance as Lyon rose to third place with 29 points from 17 games, two behind leaders Lille, 1-0 winners at Arles-Avignon on Saturday.
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Stade Rennes missed the opportunity to go second when they were held 0-0 at Girondins Bordeaux.
The Brittany side, who are fourth on 28 points, were lucky to play the whole game with 11 men as Tongo Hamed Doumbia picked up a yellow card for a violent tackle on Jaroslav Plasil in the opening minute of a dull encounter.
Bordeaux dominated throughout but were forced to share the points and remained eighth on 25 points.
Elsewhere, Monaco are fourth from bottom after a 2-0 home defeat by St Etienne, Laurent Batlles and Bakary Sako netting.
Five days after a disappointing 2-2 home draw against Hapoel Tel Aviv in the Champions League, coach Claude Puel's Lyon were barely troubled on Sunday.
Michel Bastos unleashed a powerful low shot that Matthieu Valverde parried straight into the path of Lisandro and he headed home a simple goal after five minutes.
Brazil winger Bastos then struck the post with a 30-metre free kick as Lyon tightened their grip.
Gomis made it 2-0 in the 35th minute after collecting Lisandro's defence-splitting pass and beating Valverde with an angled shot.
France keeper Hugo Lloris was then forced to make a couple of fine saves at the other end as Toulouse tried to get back in the game.
"Although we're not perfect yet, we showed a great team spirit," Lloris was quoted as saying by sports daily L'Equipe's website as his side avoided defeat for their 10th league game in a row.
Lyon, however, experienced some injury woes. Centre-back Cris suffered groin pain and right-back Anthony Reveillere was replaced in the second half by Lamine Gassama after picking up a calf injury.
