CHICAGO -- The Cubs were in the driver’s seat for the final innings of their 6-5 win against the Pirates on Thursday night at Wrigley Field, thanks to a go-ahead two-run homer by Ian Happ in the seventh that followed a game-tying three-run shot by Rafael Ortega and put Chicago ahead for the first time all night.

But as both teams struggle through trying seasons that have them at the bottom of the National League Central, it felt fitting that a blown save for Chicago in the ninth led to a bizarre walk-off ending.

With runners at the corners in the bottom of the 11th, Happ popped a ball up to Wilmer Difo at second base. Difo couldn’t stay under it however, and as the ball fell to the infield dirt, Sergio Alcántara scored to give Chicago the walk-off victory.

“Kind of a [play] that gets made 99.9 percent of the time,” Cubs manager David Ross said. “The wind was playing some tricky stuff out there it looked like. I haven't seen many of them, but I'm glad it went our way.”

Here are a couple of observations from Chicago’s win over Pittsburgh to open the four-game set:

Happ keeps hitting

Though his 11th-inning ‘heroics’ didn’t go exactly as he’d envisioned, Happ had already taken advantage of the chance to play hero four innings earlier.

The Cubs struggled through six scoreless innings against Pirates starter Mitch Keller, but after Ortega’s homer tied the game, Happ stepped to the plate to face Pittsburgh reliever Chad Kuhl with Frank Schwindel on first base.

Happ worked a 2-2 count, and when Kuhl threw him a knuckle curve that stayed right over the heart of the plate, Happ crushed the pitch into the bleachers in right-center field. The blast marked his seventh home run since Aug. 13 and fourth in his last seven games.

“It was just getting that little change of pace, getting to the bullpen and putting some good at-bats together,” Happ said. “The guys in front did a really good job getting on base. Rafi hits that ball, Frank keeps it going, and then we're able to tack on five and that's, obviously, a huge inning for us.”

It’s no secret at this point that Ian Happ had struggled for most of 2021, as evidenced by a .200/.298/.381 slash line heading into Thursday.

A gear shifted for him in mid-August, however, as Happ has now hit safely in 15 of his last 19 games after Thursday’s win and has produced a .319 average with seven home runs and 16 RBIs over that stretch.

Thompson’s starter struggles continue

Three starts into his time in the Cubs’ rotation, Keegan Thompson’s development has not come along the way Chicago had hoped it would.

Thompson was subjected to a seemingly quick leash from Ross on Thursday, as he came out after just 1 2/3 innings in his shortest outing as a starter.

Thompson left the mound with runners at the corners following a five-pitch walk to Keller and a single by Pittsburgh center fielder Bryan Reynolds. Despite Adrian Sampson escaping that second-inning jam with the three-run deficit intact, it didn’t change the result of what was another tough first inning for Thompson.

For the third straight outing, Thompson couldn’t keep the opposing lineup off the board in the first inning (this time around, Pirates first baseman Colin Moran hit a three-run homer that put his team up until the seventh inning). Thompson also passed the 30-pitch mark in the opening frame for the third consecutive game after needing 31 to get out of the first on Aug. 21 against the Royals and 38 to escape the frame against the White Sox.

“I was trying anything I could think of. I just couldn't find anything,” said Thompson about trying to make in-game adjustments. “It was one of those days where it's just, I'm in a rough patch right now. Just go back and work on my mechanics and get back in sync and go from there.”

Thursday was the quickest hook Ross had for Thompson, as he failed to pitch into the second inning or throw at least 60 for the first time in four career starts. Now, Thompson will again have to search for solutions to another tough outing.

“I think it's something that he's got to figure out. He's got to be better,” Ross said. “I mean, that's the bottom line.”