PALM SPRINGS, Calif. — The Oregon State baseball team remained unbeaten on Monday morning with a 5-4 win over UC Riverside.

PALM SPRINGS, Calif. — The Oregon State baseball team remained unbeaten on Monday morning with a 5-4 win over UC Riverside.

But the Beavers had to go into extra innings to snag the victory.

OSU senior Joey Matthews doubled to left with one out in the 11th for the win at Palm Springs Stadium.

Kavin Keyes singled to open the inning and moved to second when Dylan Davis laid down a sacrifice bunt. Jerad Casper was then intentionally walked and Zane Yanzick came in as a pinch runner at second for Keyes.

Matthews' double came off UC Riverside reliever Donovan Gonzales and went to the warning track in left, enabling Yanzick to come home with the game-winning run.

The win pushed OSU to 4-0 for the first time since the 2007 club started the season 7-0.

Freshman Max Engelbrekt picked up the win after going 22/3 innings of scoreless relief. He struck out one and is 1-0 on the year.

Junior Tyler Painton made his OSU debut and worked six scoreless innings.

UC Riverside tied the game in the ninth on a fielder's choice that netted two runs.

The Beavers had taken a 3-2 lead in the third when Michael Conforto singled up the middle. OSU extended the lead to 4-2 when Tyler Smith reached on an infield single in the seventh.

Davis got the start and he worked one inning, allowing two runs and three hits while walking two.

UC Riverside (1-3) scored its two first-inning runs off Phil Holinsworth's double, which brought in David Andriese and Joe Chavez.

The Beavers scored two runs in the bottom half of the first. Smith walked and scored from first when Jake Rodriguez doubled to straightaway center. Rodriguez moved to third on a wild pitch and scored when Keyes singled up the middle.

Keyes led the Beavers with two hits.

OSU heads to San Diego State Thursday to open a four-game series with the Aztecs at Tony Gwynn Stadium.

OREGON 4, HAWAII 2 — At Honolulu, J.J. Altobelli went 3-for-4 with two RBIs and a run scored to lead Oregon past in the finale of a four-game series at Les Murakami Stadium.

The Ducks (4-0) completed a season-opening four-game sweep with the win, their best start to a season since the sport returned in 2009. Oregon last won its first four games in 1981 when UO got off to a 5-0 start.

Altobelli's big game capped a strong opening series for the senior shortstop. He batted .462 (6-for-13) while tying for the team lead with four RBIs.

Hawaii (0-4) took an early lead, scoring a run in the bottom of the first inning for the second straight game. Andre Real, who led off the Rainbow's inning with a base on balls off Oregon starter Jeff Gold, scored on a Marc Flores ground ball to second baseman Aaron Payne.

Gold regrouped after allowing the first inning run, and held the 'Bows scoreless over the next 32/3 innings before being forced to leave the game after taking a line drive off the leg with two outs in the fifth. Gold allowed just one run on five hits in 42/3 innings.

Oregon took the lead in the top of the fifth with three runs. Steven Packard opened with a lead-off walk and moved to third on a double to left field by Shaun Chase.

Altobelli picked up his first RBI with a single to center field that scored Packard. Chase moved to third on the hit and scored on a Payne sacrifice fly to give Oregon the 2-1 lead. Brett Thomas made it 3-1 by driving in Altobelli with a double to center field.

Altobelli pushed the lead to 4-1 in the top of the sixth with an RBI single to left that scored Kyle Garlick.

Hawaii answered with a run in its half of the sixth, but the Ducks' bullpen shut down the Rainbows over the final three innings to clinch the series sweep.

Sophomore Jordan Spencer picked up the win after replacing Gold in the fifth. Spencer allowed a run and struck out two in 12/3 innings. All-American Jimmie Sherfy, pitching for the third straight day, picked up his second save. Darrell Hunter and Christian Jones also came out of the bullpen to hold Hawaii scoreless over the final three innings.

Oregon opens a three-game home series on Friday against Loyola Marymount (2-1).