Nadal's incredible act of courage amid injury pain

One particular moment late in Rafael Nadal's loss to Marin Cilic summed up the Spaniard's absolute class and character.

Nadal received treatment to his upper leg in the fourth set on Tuesday night, before he succumbed while down a break in the fifth set with Cilic leading 3-6 6-3 6-7 (7-5) 6-2 2-0.

PARTING SHOT: Nadal takes aim at tour organsiers after sad exit

However as you can see in the video above, Nadal appeared on the verge of calling it quits one game earlier, before he attempted to play on.

After Cilic took a 1-0 lead in the fifth set, Nadal made a slow walk towards the net in what looked to be his final act.

Nadal was clearly gutted. Image: Getty

However at the last second he made a left-turn and headed for his chair, fooling commentators.

"I think it's over guys," John Fitzgerald said from courtside, before realising Nadal was playing on.

"Gee I thought he was going to walk to the net there."

Todd Woodbridge agreed: "He thought about it didn't he?"

The Spaniard only lasted one more game before pulling the pin, but he put on an incredibly gutsy display in the match's final moments.

After going down 0-40, Nadal batlled back to deuce before Cilic finally put the World No.1 out of his misery, prompting Nadal to walk around the net and shake hands.

It was just the second time in his illustrious career that he's retired hurt, after also doing so in his 2010 Australian Open quarter-final against Andy Murray.

As commentators pointed out, Nadal is always hesitant to call it quits prematurely, not wanting to disrespect his opponent and rob them of the glory.

He famously played on after suffering a debilitating back injury in the 2014 Australian Open final against Stan Wawrinka, despite being completely hampered.

Fans took to social media to commend Nadal on his gutsy effort on Tuesday night:

Nadal will undergo scans on Wednesday to determine the exact nature and severity of the injury.

He called for the trainer for the first time down 1-4 in the fourth set and received treatment high on his right leg by the side of the court.

"It's not my hip, but I can't tell you exactly the muscle," a despondent Nadal told reporters after he limped slowly into his post-match press conference in obvious discomfort.

"It's high on the leg.

"We'll communicate what's going on after I have an MRI (on Wednesday)."

with AAP