Their game was ragged, their shooting frigid and their hold on the ball slippery. Just when the Trail Blazers seem headed for a disappointing loss to the Phoenix Suns on Wednesday, they got a big lift from an unexpected source:

Thomas Robinson.

The second-year forward gave the Blazers a huge jolt of energy in the fourth quarter, when he scored nine crucial points, to help Portland to a 90-89 victory before 19,537 at the Moda Center.

The win, over one of the NBA’s biggest surprise teams, was the fourth in a row for Portland (6-2) and came as the Blazers were set to embark on their first extended trip of the season, a four-gamer to the East Coast.

They would have been headed to Boston with a bitter taste in their mouths after a tough night offensively in which they shot 38.1 percent from the field and committed 14 turnovers in the first three quarters. But there was Robinson, who tied his career-high 15 points and added eight rebounds and gave Portland just what it needed. It was the first time in his NBA career that Robinson led his team in scoring.

“He came in, changed the complexion of the game, changed the speed and pace of the game,” said guard Wesley Matthews, who made two key three-pointers in the fourth quarter. “We still didn’t shoot well, but the energy that he came in with, got us going, got the crowd into it.”

Robinson used his great athleticism to provide one of the season’s highlights. With Phoenix leading 77-69, LaMarcus Aldridge missed a jumper that caromed high off the rim. Robinson swooped in, grabbed the ball with his right hand and dunked it over Markieff Morris while Marcus Morris closed in behind him.

The dunk, with 8:02 left, came over two of his former Kansas teammates, and it sent the Moda Center crowd into the frenzy. Matthews followed with a three-pointer 31 seconds later, sending the game to a frantic finish.

“Thomas Robinson came in, gave us a lot of energy and got us back into the game,” Blazers coach Terry Stotts said. “That sparked the team, sparked the crowd, just got us into it.”

The performance came two nights after Robinson had his shortest stint of the season, playing just five minutes in the first half of a home win over Detroit. Stotts said that night that he did not go back to Robinson because Joel Freeland had been playing so well.

On this night, Aldridge picked up two early offensive fouls, and Robinson got an early first-quarter call. His play in the fourth prompted Stotts to play him 10 minutes in the quarter.

“I know I only played five minutes last game,” Robinson said. “You never know what happens. L.A. came out, got two quick fouls, and my name was called. You just can’t hold onto it.”