Ryu Hyun-jin wasn't at his best for the Toronto Blue Jays in his return from the injured list (IL), though he didn't need to be for his second win of the season.

The South Korean left-hander gave up four runs on six hits in five innings against the Oakland Athletics in Oakland on Thursday (local time), as the Blue Jays beat the A's 10-4. The four runs tied Ryu's season high, as his ERA went up from 2.60 to 3.31. His record is even at 2-2.

Ryu was activated from the 10-day IL just in time for this game, after being sidelined with a right gluteal strain. The injury forced Ryu to leave his previous start on April 25 against the Tampa Bay Rays after a season-low 3 2/3 innings. Though the Blue Jays said then it was a minor issue, they still placed the 34-year-old on the IL three days later, retroactive to April 26.

Ryu ended up missing just one turn in the starting rotation.

A's leadoff man Mark Canha greeted Ryu with a solo home run in the bottom of the first, crushing an 88.2 mph fastball -- only Ryu's second pitch of the game -- and sending it into the left field seats at Oakland Coliseum. All four home runs that Ryu has served up this year have come against fastballs.

Ryu settled down and retired the next three batters in a row, two via strikeouts. In the second inning, Ryu gave up a single but got a flyout and a double play ball to keep the A's at bay.

The Blue Jays handed Ryu a 3-1 advantage with one swing of the bat in the third, thanks to Randal Grichuk's three-run home run.

But the starter failed to make it stand in the bottom half of that inning, as the Athletics knocked Ryu around for three runs on three hits, including an RBI double by Matt Olson and a two-run single by Sean Murphy.

With shakier-than-usual command, Ryu needed 32 pitches to get out of that inning.

But Ryu's batterymate, Danny Jansen, came through with his bat in the top of the fourth, as his two-run homer put the Jays ahead 5-4.

And Ryu's fastball velocity ticked up as the game went on. He had his first clean inning in the fourth, and his hardest four-seamer of the day, clocked at 90.8 mph, came in the fifth-inning strikeout of Tony Kemp.

In the back-and-forth affair, Ryu survived one last jam in that same fifth inning. After two outs, Ramon Laureano dumped what looked to be a harmless single to right field. But right fielder Teoscar Hernandez let the ball trickle through his legs and roll all the way to the wall, allowing Laureano to take third base as the potential tying run.

Facing the dangerous Olson, Ryu got his final strikeout of the day with a changeup.

Ryu could breathe a bit easier after his teammates erupted for four runs in the sixth to open up a 9-4 lead. Hernandez atoned for his earlier miscue with a two-run single, and Grichuk followed up with a two-run double to cap off his five-RBI performance.

Former Oakland star Marcus Semien drilled a solo home run in the seventh for a 10-4 lead, part of a 4-for-6 day at the plate.

The Blue Jays earned a split in the four-game series against the A's after dropping the first two. They'll travel to Houston to face the Astros for a three-game set beginning Thursday. (Yonhap)