| 12 ago 2026 | Stefansson, Vignir Vatnar 2529 | Heimisson, Hilmir Freyr 2338 | 1-0 | A06 Apertura Zukertort | Split Chess Open 2026 | 51 | Ver |
| 9 ago 2026 | Plenkovic, Zdenko 2350 | Stefansson, Vignir Vatnar 2529 | 0-1 | B29 Defensa Siciliana: Nimzowitsch Variation, Closed Variation | Split Chess Open 2026 | 41 | Ver |
| 9 ago 2026 | Stefansson, Vignir Vatnar 2529 | Baasansuren, Erdene 2406 | ½-½ | D38 Gambito de Dama rehusado: Ragozin Defense | Split Chess Open 2026 | 20 | Ver |
| 9 ago 2026 | Tokhirjonova, Gulrukhbegim 2355 | Stefansson, Vignir Vatnar 2529 | 0-1 | E05 Apertura Catalana: Open Defense, Classical Line | Split Chess Open 2026 | 67 | Ver |
| 8 ago 2026 | Stefansson, Vignir Vatnar 2529 | Stankovic, Boris 2304 | 1-0 | A00 Apertura Húngara: Symmetrical Variation | Split Chess Open 2026 | 67 | Ver |
| 7 ago 2026 | Sale, Srdjan 2245 | Stefansson, Vignir Vatnar 2529 | 0-1 | C00 Defensa Francesa: King's Indian Attack | Split Chess Open 2026 | 53 | Ver |
| 6 ago 2026 | Stefansson, Vignir Vatnar 2529 | Pijpers, Arthur 2491 | ½-½ | D85 Defensa Grünfeld: Exchange Variation, Modern Exchange Variation | Split Chess Open 2026 | 8 | Ver |
| 6 ago 2026 | Nikcevic, Nebojsa 2316 | Stefansson, Vignir Vatnar 2529 | ½-½ | E10 Defensa India: Anti-Nimzo-Indian | Split Chess Open 2026 | 36 | Ver |
| 6 ago 2026 | Stefansson, Vignir Vatnar 2529 | Kelbl, Jakob 2090 | 1-0 | B10 Defensa Caro-Kann: Goldman Variation | Split Chess Open 2026 | 49 | Ver |
| 4 ago 2026 | Stefansson, Vignir Vatnar 2529 | Savitha Shri B 2375 | 1-0 | D43 Defensa Semieslava: Moscow Variation | 35th Kavala Open Chess Tournament \"Vasilis Theodoridis\" | Group A | 67 | Ver |
| 3 ago 2026 | Kavutskiy, Kostya 2310 | Stefansson, Vignir Vatnar 2529 | 0-1 | A15 Apertura Inglesa: Anglo-Indian Defense, King's Indian Formation, Double Fianchetto | 35th Kavala Open Chess Tournament \"Vasilis Theodoridis\" | Group A | 35 | Ver |
| 2 ago 2026 | Veleshnja, Zino 2227 | Stefansson, Vignir Vatnar 2540 | 0-1 | A27 Apertura Inglesa: King's English Variation, Three Knights System | 35th Kavala Open Chess Tournament \"Vasilis Theodoridis\" | Group A | 60 | Ver |
| 1 ago 2026 | Stefansson, Vignir Vatnar 2540 | Noy, Eyal 2314 | 0-1 | A28 Apertura Inglesa: King's English Variation, Four Knights Variation, Flexible Line | 35th Kavala Open Chess Tournament \"Vasilis Theodoridis\" | Group A | 28 | Ver |
| 20 jun 2026 | Stefansson, Vignir Vatnar 2610 | Ulfarsson, Magnus Orn 2313 | 1-0 | E11 Defensa Bogoindia: Nimzowitsch Variation | Green Diamond Invitational 2026 | 36 | Ver |
| 20 jun 2026 | Johannsson, Orn Leo 2368 | Stefansson, Vignir Vatnar 2610 | 0-1 | D02 Apertura de Peón de Dama: Krause Variation | Green Diamond Invitational 2026 | 37 | Ver |
| 20 jun 2026 | Stefansson, Vignir Vatnar 2610 | Thorfinnsson, Bragi 2283 | 1-0 | D37 Gambito de Dama rehusado: Three Knights Variation | Green Diamond Invitational 2026 | 48 | Ver |
| 20 jun 2026 | Stefansson, Hannes 2445 | Stefansson, Vignir Vatnar 2610 | 0-1 | B29 Defensa Siciliana: Nimzowitsch Variation, Closed Variation | Green Diamond Invitational 2026 | 33 | Ver |
| 20 jun 2026 | Stefansson, Vignir Vatnar 2610 | Gretarsson, Helgi Ass 2412 | 1-0 | B06 Defensa Moderna: Two Knights Variation | Green Diamond Invitational 2026 | 51 | Ver |
| 20 jun 2026 | Thorfinnsson, Bjorn 2396 | Stefansson, Vignir Vatnar 2610 | 0-1 | A40 Horwitz Defense | Green Diamond Invitational 2026 | 33 | Ver |
| 19 jun 2026 | Hjartarson, Johann 2467 | Stefansson, Vignir Vatnar 2540 | 0-1 | B29 Defensa Siciliana: Nimzowitsch Variation, Advance Variation | Green Diamond - Final Four | 39 | Ver |