Britain's Dan Evans landed the best win of his career and biggest shock of the Australian Open so far as he knocked out seventh seed Marin Cilic in four enthralling sets.
Evans had never before beaten a top-10 player at a grand slam but the 26-year-old from Solihull played the match of his life to seal a 3-6 7-5 6-3 6-3 victory.
He will now face either Victor Estrella Burgos of the Dominican Republic or, more likely, Australia's 27th seed Bernard Tomic in the third round.
Evans scored his first ever top 10 scalp en route to the Sydney International final last week against world number eight Dominic Thiem, but not only is Cilic one place higher than the Austrian, the scale and stage of this triumph gives it far greater significance.
Stan Wawrinka had to save a match point against Evans before winning the US Open in September but this time the British number three was never going to let the opportunity slip.
He was quicker, cleverer and more consistent than Cilic, who at 6ft 6in towered above Evans in stature but was out-thought and out-fought in front of a packed-out crowd on Court Three.
Evans' victory means he has now reached three consecutive grand slam third rounds and continues a remarkable rise that has seen him surge from 319th in the world this time two years ago, to 52nd.
Cilic, a US Open champion in 2014 and now coached by Jonas Bjorkman, once of Andy Murray's team, showed his class in the opening set but Evans helped him on his way as two missed forehands and a double fault gave away a break for 3-0.
Evans had a sniff at 4-2 when he opened up 0-30 but Cilic came back to hold, one whipped crosscourt forehand prompting Evans to comment "too good".
The second set looked to be going a similar way when Cilic created three break points in the first game but Evans dug deep to hold, overcoming a rare foot-fault along the way, albeit with a few mutterings under his breath.
Cilic did break soon after but Evans was not deterred, responding in kind the very next game with a superb, chiselled backhand pass that drifted inside the line.
At 5-5, a gutsy backhand smash held off two more Cilic break points and now, serving to stay in the set, it was the Croatian's turn to wobble.
Another scintillating backhand pass, this time ripped down the line, gave Evans two set points and he converted at the first time of asking when a Cilic forehand flew long.
Jogging into the change of ends, the momentum was now with the Briton. He broke again at 2-1 in the third, when a review showed Cilic's forehand wide, and served out to love to move a set in front.
Into the fourth and a marathon 15-minute second game, featuring nine deuces, and in which Evans rescued no fewer than eight break points.
As Evans held, pumping his fist, it felt like a fatal blow for Cilic and sure enough Evans broke himself at 3-2 to put victory within his grasp.
Serving to stay in the match at 5-3, Cilic crumbled, a double fault and then a limp forehand into the net handing Evans three match points.
Cilic saved two but not the third as another missed forehand, his 31st of the contest, confirmed Evans' progress after two hours and 58 minutes.