Although cleared of a stamping charge from the first test after treading on Lions lock Alun Wyn Jones, Horwill must face a second hearing on Monday after the International Rugby Board controversially re-opened the case.
He would likely miss the series-decider in Sydney if sanctioned.
"He leads by example in all facets of the game. Obviously he had his own distraction," Beale told reporters in Melbourne on Sunday, the day after the Wallabies clinched a 16-15 win in the second test.
"The way he played last night was outstanding. Full credit to him for bouncing back.
"Just the way he carried himself the whole week, his head up high. Going into training sessions with a focus on what we had to do out there.
"There was no lack of attention there, he was on the job all the time. He was always on his role. He did his job every well.
"That's what opened it up for (Adam) Ashley-Cooper's try out wide," Beale added of the Wallabies centre's late score that carried the hosts to victory.
"Without them 'piggies' running them nice tight lines and making that yardage up front, it would have been impossible for James (O'Connor) and Coops to do their job."
Australia coach Robbie Deans declined to criticise the IRB's move, which enraged the Australian Rugby Union and has been branded a 'kangaroo court' by local media.
"When I started my career as coaching I didn't think I'd need a legal background as well, but I've done an awful lot of it," Deans deadpanned.
"It'll run its course and then we'll get on with the stuff that really excites these blokes."
The IRB's move, announced on Thursday, added to a torrid leadup for Deans ahead of the second test.
An arrest warrant was issued for injured winger Digby Ioane for missing a court appearance on Monday, while James O'Connor and Beale were controversially photographed at a fast food restaurant at four in the morning on Wednesday.
Deans said he would be unable to guarantee further disciplinary problems might pop up.
"You know the industry. Who knows?" he shrugged.
"The critical thing is how you respond. It's like the game. Things are never totally as you'd anticipate or as you hope, but you've got to cope - you've got to adapt and push on.
"I'd be reasonably confident it won't happen again. Wouldn't be a good scene for these blokes if it did, or the team.
"That's the nature of the team game, you're only as good as your weak link. Opposition teams prey on those opportunities."
Both teams' captains remain in doubt for the second test, with Lions flanker Sam Warburton coming off the ground with a hamstring injury and staying in Melbourne to have a scan.
Deans said Warburton, who helped the Lions edge the Wallabies at the breakdown, had played "very well" at Docklands.
"It would be a tough pill for him to swallow if he's not able to start the (Sydney) game.
"But they've got some able replacements as well. Whoever turns out is going to be a good player."