Saudi Crown Prince Mohammed bin Salman was among dignitaries in Moscow on Thursday as his country's team suffered a 5-0 defeat against hosts Russia in the opening match of the 2018 World Cup.
Bin Salman, who is known as MbS, had not been seen in public since late April, when an influential Saudi blogger known as Mujtahidd posted reports on Twitter of gunfire near royal palaces in Riyadh, prompting weeks of speculation about his whereabouts.
Photos last week showed MbS attending the first meeting of the Saudi-Emirati Coordination Council in Jeddah with Abu Dhabi Crown Prince Sheikh Mohammed bin Zayed.
Saudi Arabia has also published images of him chairing meetings in Riyadh, but all of those photos were undated and showed MbS in official settings behind closed doors.
MbS was also seen in photos as Gulf leaders gathered in Makkah earlier this week to discuss an economic support package for Jordan.
Television coverage of Thursday's match showed MbS shaking hands with Russian President Vladimir Putin after Yuri Gazinsky headed the hosts into a first half lead at Moscow's Luzhniki Stadium.
The handshake came despite Russia and Saudi Arabia backing different sides in the war in Syria, where Russia has played a leading military role supporting the Syrian government while Saudi Arabia has backed opposition rebel groups.
Denis Cheryshev added another for Russia before halftime and Artem Dzyuba headed home after 70 minutes to leave the Saudis reeling.
Cheryshev then smashed in his second goal and Aleksandr Golovin scored from a freekick in the final minutes to wrap up a comfortable Russian win in which the Saudis failed to test Russian goalkeeper Igor Akinfeev.
The heavy defeat leaves Saudi Arabia likely needing to beat Uruguay in their next match on Wednesday to stand a realistic chance of advancing beyond the group stage of the tournament.
Egypt, the other team in Group A, face the South American side on Friday in Ekaterinburg, and Egypt and Saudi Arabia then play each other in a 'Red Sea derby' match in Volgograd on 25 June.
Morocco, Tunisia and Iran are also among the tournament's 32 finalists.
The Russian foreign ministry on Thursday also published photos of a meeting between Putin and MbS at the Kremlin, in which the pair discussed closer cooperation between the countries' oil industries.
"I think that the whole world benefited from this cooperation, as the volatility in oil prices, as well as other volatility occurring in this sphere, and the stabilisation achieved in this sphere helped to stabilise the entire global economy," bin Salman was quoted as saying.
"The benefit to our two countries has been a benefit to all countries that use our energy. We have been witnessing this beneficial effect over the past several years. Undoubtedly, we would like to continue this cooperation and go even further."