Croatia will meet Australia in the semi-finals of the 2022 Davis Cup finals after securing victory over Spain in Wednesday's quarter-final tie in Malaga.

Borna Coric saw off Roberto Bautista Agut in straight sets before Marin Cilic came through a mammoth three-set battle with Pablo Carreno Busta to seal Croatia's progression and send the 2019 champions packing.

Coric took one hour and 56 minutes to see off Bautista Agut 6-4 7-6[4] in the opening match, breaking in the seventh game of the first set and saving a break point in the 10th to go 1-0 up.

Both players - Coric in particular - demonstrated a masterclass in serving to take the second set all the way to a tiebreaker, where the Croatian took four of the first five points on offer to steer clear of his Spanish counterpart.

Coric would hit 12 aces on the day, and his final one on match point put Croatia 1-0 up in the tie in front of the raucous Spanish crowd, who prepared to witness Cilic take on Carreno Busta next.

However, the break was disrupted when a pair of protestors stormed onto the court and attempted to tie themselves to the net before security quickly became involved to drag them away.

Cilic and Carreno Busta would then emerge to play out a three-hour and 13-minute thriller, which the former prevailed in 5-7 6-3 7-6[5] to send the 2018 champions through to the last four.

The opening exchanges were characterized by missed opportunities for both men, as Carreno Busta squandered five opportunities to break in Cilic's opening two service games, while the Croat missed two of his own in game three.

Carreno Busta would break for a 3-2 lead in game five before Cilic earned the break back straight away to get the contest back on serve, but the Spaniard broke once more in the 11th game before Cilic send a forehand just wide of the tramlines to cede the first set.

The Croatian majorly upped his service game in the second set, though, and he broke in the sixth game for a 4-2 lead and would level the match when Carreno Busta could only send a forehand return long.

The two men each broke one another twice more in the third set before settling the exhilarating match with a tiebreaker, where Carreno Busta let a 4-1 lead slip in a dramatic late collapse.

Cilic - who hit 20 aces and 15 double faults on the day - won six of the next seven points on offer and sealed the deal when a tired forehand from Carreno Busta went long, with the Croatian team already celebrating before the ball had come back down.

Croatia will do battle with Australia following their 2-0 success over the Netherlands on Tuesday, while Italy will tackle the USA and Germany will pit their wits against Canada in Thursday's remaining quarter-final ties.