Alonso’s goal keeps Sounders afloat

Another poor start in a playoff series for Sounders FC, but it could have been much worse.

Midfielder Osvaldo Alonso salvaged a desperately needed goal in the 90th minute as Seattle limited the damage in a loss to archrival Portland, falling 2-1 in the opener of the Western Conference semifinals in front of 38,507 at a blustery CenturyLink Field.

The Sounders must beat the top-seeded Timbers on the road by two goals in the second leg at 8 p.m. Thursday at Jeld-Wen Field to advance to the conference finals for a second straight year.

A one-goal win would send the series to extra time. A tie or loss would end the season disappointingly early for a Sounders team that had day-one expectations of making MLS Cup and a roster that looked the part.

“It’s halftime of the ‘game,’ ” said coach Sigi Schmid. “Just as they came here and won, we feel very confident we can go there and win.”

Trailing 1-0 in the second half, the Sounders allowed a second goal in the 67th minute when Portland forward Darlington Nagbe evaded a tackle in the penalty box and finished past goalkeeper Marcus Hahnemann.

Seattle nearly allowed a devastating third in the 83rd minute when Timbers forward Ryan Johnson got free on a breakaway, but the defense was just able to scramble and deflect the shot away.

How vital it was, as the Sounders pulled a goal back just before stoppage time as Alonso fired in a low shot amid a scramble of bodies in the Portland penalty area.

“That goal,” said Alonso, “gives you confidence.”

Alonso is the only Sounder to have played every minute in the team’s playoff history, and his two postseason goals are tied with Eddie Johnson for the franchise lead.

It was the first goal Seattle has scored in the first leg of a two-game series, having been outscored 9-0 in six such games before Saturday.

Much like the NFL lines and markings on the field, it wasn’t pretty, but it beats needing a multigoal win in what will be a raucous road venue.

The Sounders got out to a quick start in the first half, but it was Portland that took the lead in the 15th minute.

Johnson lost his marker, defender John Kennedy Hurtado, on a near-post run and flicked a header past Hahnemann from a cross by defender Jack Jewsbury.

The Timbers had come into the series with momentum, having routed Chivas USA, 5-0, in their regular-season finale.

The best chances for the Sounders might have come on free kicks, and there were many amid physical play.

Clint Dempsey nearly tied it in the 19th minute, but his blistering shot was denied by a spectacular diving save by Portland’s Donovan Ricketts.

Dempsey had another good look on a free kick in the 29th minute, but his powerful drive drifted just inches high. In the second half, he had a shot bounce off a defender, then the top side of the crossbar and out.

Overall, the Sounders finished with a 20-10 advantage in shots, an 11-1 advantage in corner kicks and nearly 60 percent of the possession.

“We have to keep our mentality positive,” midfielder Mauro Rosales said. “We had a good game controlling everything, and I think we’re in a good position to turn it around.”