Obafemi Martins reminded Seattle Sounders what they have been missing, scoring twice in their 4-0 victory over Orlando City.

The Sounders had lost five straight matches in MLS, scoring just one goal in that period as both Martins (groin) and Clint Dempsey (hamstring) were struggling with injuries, but they responded emphatically at CenturyLink Field on Sunday.

Martins opened the scoring in the 17th minute with a sharp finish after a one-two with Lamar Neagle, while new signing Nelson Valdez struck on debut five minutes into the second half with a trademark header.

Panamanian defender Roman Torres also made his Seattle debut, completing 90 minutes at centre-back.

Martins added Seattle's third goal just after the hour mark, impressively hurdling Orlando goalkeeper Tally Hall to poke the ball into the net, while Thomas struck the home side's fourth in stoppage time.

The win took Seattle to 35 points, although they did not move from sixth spot in the Western Conference standings, while Orlando (28) remain seventh in the East.

Seattle's struggles up front - both with goals and injuries - were underlined last week as Chad Barrett struck their first goal in five matches in the opening minute against LA Galaxy but was withdrawn with a hamstring complaint soon after as the Sounders lost 3-1.

But with Martins back - the Nigerian had scored 32 goals in two-and-a-half seasons with Seattle before Sunday - Sigi Schmid's side looked much more dangerous.

The Sounders could have scored even more with Martins having a penalty saved on the half-hour mark after Mateos hauled Chad Marshall down at a corner, while Seattle played against an undermanned Orlando for 50 minutes after Tyler Turner's red card in the first half.

Martins' brace took him to nine goals for the season.