Hirst replaced Lawrence Shankland – who scored one of Scotland’s goals – in the 62nd minute at the Sports Illustrated Stadium in New Jersey.
The damage was all done before Hirst got on the pitch, with Che Adams bagging a brace and Scott McTominay also scoring in a rampant first half for Steve Clarke’s side.
George Hirst played 28 minutes for Scotland in their 4-0 friendly win against Bolivia (Image: PA)
Clarke said: “For once, I got everything I asked for – no injuries, a performance and a good result.
“We spoke a lot this week about being more clinical and the front two were good and complemented each other well.
“As we get to this stage, we’re as well prepared as we can be. Next week is a different ball game – it’s the World Cup, Haiti are a really good side.
“We understand the type of game we’re going to get against Haiti; it’s up to us to put on a performance and play the way we need to play to get the result.”
New Rangers striker Shankland, who scored twice in Scotland’s previous game, a 4-1 win over Curacao, started up front alongside Adams.
He said: Today was our first time together from the start, and it worked well at times, so we can be pleased.
“All you can do when you get the opportunity is put your best foot forward and give the manager a decision to make when he’s picking his team.
“We’ve got a really good group, a lot of togetherness in there. No matter who is picked, we will all be ready.”
Given the good form of Shankland and Adams, Hirst appears set to start on the bench as Scotland kick off their World Cup Group C games against Haiti a week today (2am GMT).
They then face Morocco on Friday, June 19th, before finishing their group stage clashes against Brazil on Wednesday, June 24th. Both of those games kick off at 11pm GMT.