Two late goals brought a result for Rangers but it did not absolve them.

The performance against Falkirk lacked accomplishment and refinement, so progress to the fifth round of the William Hill Scottish Cup became a matter of grim perseverance. Falkirk did not muster much pressure themselves, but then they had to cope with being reduced to 10 men and so their focus turned to containment.

The reaction must have been relief for the Ibrox side, since an awkward engagement was overcome. There was immediately consternation, though, when a flare was thrown from the away end onto the pitch. It was eventually extinguished, but the synthetic surface was damaged and the Rangers directors offered to pay the repairs. The authorities may also be moved to act against a practice that is an issue for several clubs.

Flashpoints were not confined to the end of the game. Bilel Mohsni ended up in a series of arguments with Falkirk players during the celebrations following the opening goal, after his touch sent the ball to Nicky Law and the midfielder fired it home from 12 yards. Ian Black's series of kicks at Conor McGrandles also provoked the Falkirk midfielder into an angry response, and he squared up to Black to shout in his face.

"I felt he kicked me," McGrandles said. "He'd done it before twice, I was really unhappy. So I thought I'd have a wee go at him. If someone's going to kick you, you're not going to let them get away with it. He never said much, he was just staring at me. I was shouting at him. I thought it was a malicious tackle, I thought he kicked me for no reason, but sometimes players do that. I just need to get on with it."

Gary Holt, the Falkirk manager, mildly rebuked the 18-year-old midfielder for overreacting, particularly since Law was in the midst of breaking upfield at the time. Even so, McGrandles was one of several impressive young performers in the Falkirk side. They passed the ball brightly and with a little more composure in the final third they might have created some clear openings.

The visitors relied too frequently on bypassing the midfield. Long straight and diagonal balls up to Jon Daly and Nicky Clark certainly moved the play upfield swiftly, but the visitors never asserted control of the game as a result. Having faced Hibernian and Aberdeen in recent times, Falkirk are well-placed to judge how the Ibrox side might fare in the latter stages of the competition.

"Based on the two performances, I thought Aberdeen were the better team," said McGrandles. "I can't [see Rangers winning the cup], there's better teams than them in the competition, but we reached the semi-final last year. I don't think they're much better than us, but they'll do well in this league."

It was a performance of few highlights for Rangers, although Ally McCoist will take some satisfaction from the fact that his squad is developing the habit of winning games regardless of the circumstances. The visitors only impressed in sporadic moments, and they tended to come down the left flank, where Lewis Macleod and Lee Wallace are developing an effective partnership.

"I've improved a lot [by playing with better players]," Macleod said. "It was tougher [against Falkirk] because the right back was coming quite tight. It was harder to play the one-twos [with Wallace] that had been so successful last Monday night [against Arbroath] But it's a good partnership, he's different class and that makes it much easier."

Falkirk were not intimidated by the task, and once they fell behind they pressed upfield in search of an equaliser. That was a risky strategy, and Rangers took advantage when Macleod played David Templeton through and the winger shot beyond McGovern. Rangers believe they can reach the latter stages of the competition, but it will take more than confidence if the team is capable of succumbing to such mundane form.

"Whoever we got [next] we'd be happy to take them on," said Macleod. "It would be a massive achievement to get into a final whichever team you are, but especially with what's happened in the last couple of years."