Zayani's rise as a coach was a natural progression given the success he had as a player. His coaching career started soon after he retired as a player, as an assistant coach for the
Al-Ittifaq first team. That particular tenure lasted two years but he later had several stints with the club a manager, he was promoted to head coach for the first time in 1976. Al-Zayani won the
1982–83 Saudi Premier League, thus Al-Ettifaq became the first team from
Dammam to win the title and first team to win the league title undefeated, and
Khalil Al-Zayani also became the first Saudi Arabian manager to win the league title. The
1983 Gulf Club competition was also won in the same season making Al-Ettifaq the first Saudi team to win a non-domestic title. In between his Ettifaq managerial stints, he was successful as the
Saudi Arabia national team coach, a mission he first started in March 1984. Al-Zayani was called up by the national federation and asked to travel to
Muscat,
Oman to replace the sacked
Mário Zagallo, coach of the
Brazil World Cup-winning team of 1970 that featured
Pelé. Zagalo was let go after a 4–0 defeat to
Iraq as the Saudis collected only one win from their first three matches in the
7th Arabian Gulf Cup. Al-Zayani became the first Saudi head coach to manage the
Saudi Arabia national football team. Zayani, nonetheless, proved to be up to the task as he oversaw a draw against
Kuwait and was victories over the
United Arab Emirates and
Bahrain as
Saudi Arabia finished third in the competition. In August 1984, he oversaw the Saudi national football team in the
Olympic Games finals in
Los Angeles, which was considered a significant achievement at the time, but his sights were firmly fixed on the
AFC Asian Cup scheduled for December that year. Zayani called up several younger players, including players such as
Mohaisen Al-Jam'an,
Majed Abdullah and
Mohamed Abd Al-Jawad. He took
Saudi Arabia to new heights in the continent as he led the country as debutants in the
1984 AFC Asian Cup in
Singapore.
Saudi Arabia won Group A ahead of
Kuwait,
Qatar,
Syria and
Korea Republic. In the semi-finals they followed up with a 5-4 penalty shootout victory over
Iran after a 1–1 draw in extra time to qualify to the final. In the final, Al-Zayani led the
Saudi Arabia national football team to 2-0 victory over
China with goals from
Shaye Al-Nafisah and
Majed Abdullah to claim their first
Asian Cup and first senior national team title. Al-Zayani came back to coach Al-Ettifaq in 1987 for the second time, winning the
1986–87 Saudi Premier League in his first season, and the
1988 Arab Club Champions Cup together with the
1988 Gulf Club Champions Cup in his second season. Al-Zayani went on to coach
Al-Qadisiya and
Al-Hilal, as well as a third stint with Al-Ettifaq. ==Asian Cup success==