Pilkadaris, who made his maiden British Open appearance at Carnoustie in 2007, was a relieved man after ending the 36-hole qualifier with a performance that he thought had cost him his chance of making the grade.
"I played horrendous today. I put myself under lots of pressure by hitting into the trees with my drives and was always scrambling to recover," said the three-time Asian Tour winner.
The Australian, who teed off on the back-nine, got off strongly with a birdie on the 11th. However, his game started to fall apart with bogeys on 12th, 13th, 15th and 16th holes and he had to make the turn in three-over.
Pilkadaris's mixed two more bogeys with an eagle and two birdies in his inward nine to eventually return with a 72.
"I thought I had missed my chance with the way I played today. I had to wait around for a couple of hours and finally when the news came, I was really relieved," said Pilkadaris.
After closing with a 70 in regulation play, Stewart joined eight other players in a nerve-wreaking play-off to decide the fourth and final slot for The Open.
"It's pretty heart-stopping stuff out there. I've already booked a taxi to the airport and was called back for the play-off," said Stewart.
"I'm simply delighted with the way things are going and this performance definitely ranks right up there at the top for me," said the Australian who eventually prevailed in the nine-men play-off. Overnight leader, Mikko Ilonen of Finland missed out on his fifth appearance at The Open when he carded a disappointing 77 to finish in tied-20th place on 142.
"I putted really bad all day and I absolutely did not play well today, especially ending with a double-bogey on the last hole," said Ilonen.
China's other participant, Wu Ashun, started the day a shot better than Liang Wenchong on 71, and was desperately frustrated to card a 70 for 141, which meant him missing the playoff by a single stroke.
Full final scorecard:
136- Gaganjeet BHULLAR (IND) 69-67
138- LIANG Wen-chong (CHN) 72-66
139- Terry PILKADARIS (AUS) 67-72
140- Tomohiro KONDO (JPN) 67-73, Keith HORNE(RSA) 74-66, KIM Hyung-Sung (KOR)71-69, NOH Seung-Yul (KOR) 68-72, Tim STEWART (AUS) 70-70, Tadahiro TAKAYAMA (JPN) 69-71,Young NAM (USA) 70-70, Quincy QUEK (A) (SIN) 70-70, Danny CHIA(MAS)
(Stewart qualified for The Open after winning in the play-off)
141- Mardan MAMAT (SIN) 68-73, Shiv KAPUR(IND) 71-70, Andrew DODT(AUS) 70-71, Atthaphon PRATHUMMANEE(THA) 69-72, Jbe KRUGER(RSA) 70-71, Pariya JUNHASAVASDIKUL (THA) 71-70, WU Ashun(CHN) 71-70
142- Mikko ILONEN (FIN) 65-77, Scott HEND (AUS) 70-72, Ben LEONG(MAS)73-69, Thaworn WIRATCHANT (THA) 71-71, Rick KULACZ(AUS) 71-71
143- LIEN Lu-sen (TPE) 73-70, Mitchell BROWN (AUS) 68-75
144- LU Wei-chih (TPE) 71-73, Mars PUCAY (PHI) 74-70
145- Tony CAROLAN (AUS) 71-74, Anthony KANG (USA) 72-73, Adam BLYTH(AUS) 74-71, Simon DUNN (SCO) 71-74, Bryan SALTUS(USAa) 72-73
146- Masaya TOMIDA (JPN) 71-75, Yoshinobu TSUKADA (JPN) 74-72
147- Neven BASIC (AUS) 72-75
148- Rohan BLIZARD (AUS) 77-71
149- Marcus BOTH (AUS) 79-70, George COETZEE (RSA)77-72, Mark PURSER (NZL) 75-74, Guido VAN DER VALK (HOL)75-74, Keiichiro FUKABORI(JPN)72-77, Darren BECK (AUS) 72-77
150- LAM Chih Bing (SIN) 73-77, YEH Wei-Tze (TPE)75-75, Unho PARK(AUS) 74-76
151- Yasin ALI (ENG) 78-73, David BRANSDON (AUS) 72-79, Richard LEE (NZL)73-78
152- David GLEESON (AUS) 78-74, Gavin FLINT (AUS) 71-81
RTD: Artemio MURAKAMI (PHI), Chinnarat PHADUNGSIL(THA),Sushi ISHIGAKI (JPN), Zaw MOE (MYA), Rahil GANGJEE (IND), Adam Le VESCONTE (AUS), Airil Rizman (MAS), Prom MEESAWAT (THA), Angelo QUE(PHI)
(David Ferguson and Asia Tour April 2, 2009)
