Lionel Messi scored four goals as Inter Miami snapped their five-game winless streak with a 7-1 thrashing of struggling Montreal in Major League Soccer on Saturday.

Miami have endured a rocky spell since the resumption of play following the World Cup finals, losing four of their previous five games heading into Saturday's clash in Florida.

But the reigning MLS Cup champions got back to winning ways with a confident performance against Montreal, who are languishing second from bottom in the Eastern Conference.

Brazil international Casemiro, who joined Miami after the World Cup, bagged his first goal for the champions with a 20th minute header at the Nu Stadium.

Montreal though hit back with a 37th-minute goal from Fabian Herbers, the German midfielder's low shot from the edge of the area squeezing into the bottom corner.

But Miami did not have to wait long to regain the lead, and went 2-1 up when a low curling free-kick from Messi somehow bamboozled Montreal goalkeeper Thomas Gillier in the 40th minute.

Messi then extended Miami's lead shortly after half-time, the 39-year-old Argentina superstar's momentum helping him weave through a cluster of Montreal defenders before drilling a shot into the bottom corner.

Messi played a key role in Miami's fourth, laying on a superbly flighted pass to send former Barcelona team-mate Luis Suarez bearing down on goal. Suarez made no mistake with the finish to seal an emphatic win.

Messi secured his hat-trick on 83 minutes when he latched on to a Rodrigo De Paul pass in the 83rd minute and delicately dinked over the advancing Gillier to make it 5-1.

Teenage substitute Alex Shaw added a sixth goal in the 89th minute, rifling home a low shot from outside the area.

But there was still time for Messi to score a fourth, the veteran curling in a trademark free kick from the edge of the area in the dying minutes of stoppage time.

The victory leaves Miami in second place in the Eastern Conference, seven points behind leaders Nashville, who were playing later Saturday.