A determined Brumbies side has fallen to the Lions, 42-24, in Johannesburg.
Leading by three points with 20 minutes to go, the Brumbies' numbers dwindled, with Rory Arnold red-carded over a swinging arm tackle on Elton Jantjies, before Sam Carter was sent to the bin for ruck infringements, leaving them with 13 men.
The Lions turned a three-point hole into an 18-point advantage in that final 20 minutes, ending the Brumbies' hopes of an upset win in South Africa.
Though they worked hard to defend their own line, the weight of numbers eventually stacked up against the Canberra side, with the Lions piling on three tries in the final quarter.
Tom Banks gave the Brumbies the perfect start, finishing off a seven-phase play, beating a defender and scoring in the corner in just the second minute.
The Lions tried to use their forward might to push over a try, but Andy Muirhead kept Robbie Coetzee from dotting down, and his defensive desperation saved another try from winger Sylvian Muhuza.
Rohan Janse Van Rensburg made it third time lucky for the Lions, beating three Brumbies defenders close to the line to even things up.
Tevita Kuridrani nabbed one back for the Brumbies, in his 100th match, beating a host of Lions defenders to score and snatch back the lead.
Scrum control swung the Lions’ way as the first half wore on, with Scott Sio a repeat offender, and things began to look dire, when Rory Arnold was binned for a cynical maul collapse.
Immediately, the Lions mauled their way over the line, as the game slowed down to a grind.
Given the opportunity for points, Brumbies co-captain Christian Lealiifano took them, slotting a three-pointer, but it was the Lions who went into half-time ahead, after a second maul try on the half-time siren.
The Brumbies were forced to defend early in the second, but Banks made the most of a half-chance, to put the Brumbies back on top of a seesawing contest, and inject some optimism into his side.
The Canberrans grew in confidence from that point as the Brumbies’ fresh, and a spectacular run from Christian Lealiifano put them in a dangerous spot, before Allan Alaalatoa knocked on.
Uncharacteristic errors from the Lions meant the Brumbies were able to eke out some more momentum, but all of their tireless defensive efforts were undone by their own discipline problems.
Arnold’s night was ended after the lock collected Elton Jantjies high in a swinging arm tackle, picked up by the TMO.
When Sam Carter was sent to the bin for repeated offences, the Brumbies’ record player began spinning again, repeating the pattern of so many of their matches this season, and a third Lions maul try made it a four-point hole.
That was the only score the Lions managed with Carter off the field, though, a testament to the Brumbies’ fight, but the hosts were heaping the pressure on in the scrum, with inside back Kyle Godwin packing down on the flank.
Lions replacement flyhalf Shaun Reynolds broke through the Brumbies' dogged defensive line, to score what loomed as the inevitable match sealer, with six minutes left, before Lourens Erasmus added another.
Compounding the disappointment for the Brumbies, youngster Rob Valetini had to be helped off the field in the 74th minute, though it's unclear exactly what his injury is.
Valetini only returned to the side last week, after an early-season knee injury.
The Brumbies head to Pretoria next week to take on the Bulls, in the second leg of their South African tour.
Tries: Van Rensburg, Coetzee, Dreyer, Schoeman, Reynolds, Erasmus
Cons: Jantjies 6
Tries: Banks 2, Kuridrani
Cons: Lealiifano 2
Yellow Cards: Rory Arnold (29’), Sam Carter (62')
Red Cards: Rory Arnold (60')