Elih Villanueva pitched his strongest game Saturday night since joining the Portland Sea Dogs in June.

“It’s the best I’ve felt since the surgery,” said Villanueva, who underwent Tommy John surgery on March 31, 2016.

Villanueva, 30, allowed two runs on four hits and no walks over 61/3 innings, striking out seven.

But the Portland Sea Dogs couldn’t back him up and lost 4-3 to the Reading Fightin Phils before a crowd of 7,124 at Hadlock Field.

Chad De La Guerra and Jeremy Barfield homered for Portland (40-44).

It was an encouraging outing for Villanueva, a 2008 Florida Marlins draft pick out of Florida State.

Villanueva made one major league appearance for the Marlins in 2011, moved on to the Orioles’ system in 2015 and was planning to pitch in Taiwan in 2016 before his arm gave out.

Now he’s on the rebound, mixing in a 91 mph fastball with sliders, curves and change-ups.

“A lot about the arm being healthy is being able to throw those breaking balls,” he said. “It’s been a long, drawn-out process, building from start to start.”

Luis Ysla (1-5) entered and walked two batters on eight pitches, loading the bases. Cord Sandberg hit a slow bouncer to first baseman Mike Holt, who rushed his throw to second. The ball hit the runner and bounced into left field, allowing two runs to score.

The Phils (51-35) added a run off Ysla in the ninth, which proved to be the difference after Barfield homered in the bottom of the ninth.

Reading starter Cole Irvin (3-0) allowed two runs on three hits in eight innings, including De La Guerra’s home run in the first and Deiner Lopez’s RBI single in the fifth.

Victor Arana relieved Irvin in the ninth. Barfield greeted him with a blast over the left-field wall. But Arana retired the next three batters for his fifth save.

NOTES: De La Guerra’s home run was his second since joining the Sea Dogs. He’s batting .343 in 14 games. … Barfield hit his eighth home run in his 40th game with Portland. … Ysla’s ERA is now 5.26. … Outfielder Joseph Monge was activated from the disabled list. Monge, batting .231, had not been with Portland since June 11. He just finished a rehab assignment with Lowell. …

Portland hit grand slams on consecutive days, Barfield on Thursday and Olt on Friday, and now have four this season (the others were by Jordan Procyshen and Devers). The franchise record is six in 2008 (Lars Anderson had two, plus Aaron Bates, Bubba Bell, Zach Daeges and Andrew Pinckney). … Left-hander Henry Owens makes his second start Sunday since he was sent down from Triple-A Pawtucket. He failed to get out of the first inning in his first start.

Kevin Thomas can be contacted at 791-6411 or at:

[email protected]

Twitter: KevinThomasPPH