BALTIMORE -- Awesome is a good word to describe the Orioles' doubleheader against the Pirates. It's so apropos that Manny Machado used it liberally following his first game of the season.
Machado made his season debut in the second game of Thursday's doubleheader, and Matt Wieters made it a winning one thanks to a walk-off home run in the bottom of the 10th inning for a 6-5 Orioles victory.
Leading off the 10th, Wieters clubbed his fifth home run of the season down the right-field line off reliever Stolmy Pimentel. Both teams had left the bases loaded in the eighth. Pittsburgh stranded 15 runners.
Machado, who last played on Sept. 23 and underwent surgery on his knee in October, went 0-for-5 in front of excited fans who roared for the star third baseman in his return.
"It was awesome. It was awesome. First day back, walk-off win," Machado said. "Great game, great pitching staff, great two games. Couldn't be happier."
Playing for the first time since Sunday, the Orioles swept the doubleheader after capturing the opener, 5-1, and improved to 3-0 in extra-inning games.
Fans also cheered as the Orioles first tied the score at 4 with four runs in the sixth inning, then again in the seventh for Nick Markakis' solo home run after Pittsburgh scored in the top of the inning.
The final roars came following the second pitch in the bottom of the 10th inning of a nearly four-hour game that ended just before 1 a.m. ET on Friday.
"It was long for me, and I only played half of it," said Wieters, who did not play in Game 1. "It's nice to get a win. It's nice to be able to get a team win where we had to battle back and come back and score some runs."
Tommy Hunter (1-0), Baltimore's seventh pitcher in the game, worked two-thirds of an inning. Pimentel (2-1) faced only one batter.
One of baseball's rising stars with both the bat and the glove, Machado was expected to return on Tuesday and then Wednesday following a rehab stint, but rain caused postponements, leading to Thursday's doubleheader. The Orioles activated him for the opener, but his return to the field came in the second game, which began at 8:56 p.m. following a 46-minute rain delay.
The orange-clad crowd roared for the 21-year-old Machado even before he took the field, rising when his face appeared on the scoreboard during pregame introductions.
But he didn't get the ball out of the infield, grounding out in his first four at-bats and popping out to second in the ninth. He had a clean night defensively.
"I think what we missed as much as anything is the stability he gave us in the infield," manager Buck Showalter said of Machado. "I kept asking him after about the sixth inning how he felt, and he finally gave me that look like, 'Don't ask me anymore.'"
Pittsburgh scored single runs in the fifth, sixth and seventh innings after tallying two in the first off Chris Tillman, who lasted 4 2/3 innings. Hunter, Darren O'Day and Brian Matusz each pitched both ends of the doubleheader, combining to throw 4 2/3 shutout innings
Wieters was one of five Orioles with two hits. The Pirates' Gaby Sanchez had four hits and an RBI.
Trailing, 4-0, the Orioles scored four in the sixth inning on four consecutive two-out hits. After chasing Pittsburgh starter Brandon Cumpton, Baltimore tied the score on J.J. Hardy's two-run single. Steve Pearce, the Game 1 hero thanks to his three hits, scored the tying run after catcher Chris Stewart dropped the relay throw, which easily beat Pearce home.
Tillman labored for his second straight outing, allowing three runs on six hits with three walks and eight strikeouts. He threw 49 pitches in the first inning alone -- 112 overall -- and the Pirates fouled off 16 of those offerings.
The right-hander pitched into the fifth but left after two outs. He surrendered two extra-base hits in the inning, including Sanchez's soaring RBI triple off the right-field wall, which gave Pittsburgh a three-run lead.
Ike Davis added the Pirates' fourth run with a run-scoring single in the sixth off reliever Evan Meek.
"If we score five [runs on] nine [hits], we feel like we're going to win here," Davis said after Pittsburgh's third straight loss and seventh in eight games. "Obviously, we faced some tough pitching today."
The game also served as the season debut for pitcher Troy Patton, who was charged with a run in the seventh. The Orioles activated Patton between Games 1 and 2 and outrighted right-hander Josh Stinson to Triple-A Norfolk.
Benjamin Standig is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.