The Scottish side went on to win two of those remaining three games, with last weekend's 32-10 win over Ulster guaranteeing home advantage in their semi-final against the same opponents on Friday night.
And Horne is looking to return to try-scoring form once more as he attempts to top off a successful season for the Warriors by helping them achieve play-off glory.
"I've just been keeping my head down this season, working really hard and trying to improve my game all the time," he told the club's official website.
"The Cardiff game was a highlight but I think that's all thanks to Tommy (Seymour) and Finn (Russell) for putting me through the gaps.
"It's great that the coaches are pleased with how I've been playing and we've got a massive end to the season coming up.
"Hopefully I can keep this form going and we'll get a big win this weekend."
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